WorldWideScience

Sample records for high altitude studies

  1. High altitude syndromes at intermediate altitudes: a pilot study in the Australian Alps.

    Science.gov (United States)

    Slaney, Graham; Cook, Angus; Weinstein, Philip

    2013-10-01

    Our hypothesis is that symptoms of high altitude syndromes are detectable even at intermediate altitudes, as commonly encountered under Australian conditions (flatus expulsion (HAFE). Symptoms of high altitude syndromes are of growing concern because of the global trend toward increasing numbers of tourists and workers exposed to both rapid ascent and sustained physical activity at high altitude. However, in Australia, high altitude medicine has almost no profile because of our relatively low altitudes by international standards. Three factors lead us to believe that altitude sickness in Australia deserves more serious consideration: Australia is subject to rapid growth in alpine recreational industries; altitude sickness is highly variable between individuals, and some people do experience symptoms already at 1500 m; and there is potential for an occupational health and safety issue amongst workers. To test this hypothesis we examined the relationship between any high altitude symptoms and a rapid ascent to an intermediate altitude (1800 m) by undertaking an intervention study in a cohort of eight medical clinic staff, conducted during July of the 2012 (Southern Hemisphere) ski season, using self-reporting questionnaires, at Mansfield (316 m above sea level) and at the Ski Resort of Mt Buller (1800 m), Victoria, Australia. The intervention consisted of ascent by car from Mansfield to Mt Buller (approx. 40 min drive). Participants completed a self-reporting questionnaire including demographic data and information on frequency of normal homeostatic processes (fluid intake and output, food intake and output, symptoms including thirst and headaches, and frequency of passing wind or urine). Data were recorded in hourly periods extending over 18 h before and 18 h after ascent. We found that the frequency of flatus production more than doubled following ascent, with a post-ascent frequency of approximately 14 expulsions per person over the 18 h recording period (Rate

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

    NARCIS (Netherlands)

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

    2000-01-01

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

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

    NARCIS (Netherlands)

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

    2000-01-01

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

  4. Joseph Barcroft's studies of high-altitude physiology.

    Science.gov (United States)

    West, John B

    2013-10-15

    Joseph Barcroft (1872-1947) was an eminent British physiologist who made contributions to many areas. Some of his studies at high altitude and related topics are reviewed here. In a remarkable experiment he spent 6 days in a small sealed room while the oxygen concentration of the air gradually fell, simulating an ascent to an altitude of nearly 5,500 m. The study was prompted by earlier reports by J. S. Haldane that the lung secreted oxygen at high altitude. Barcroft tested this by having blood removed from an exposed radial artery during both rest and exercise. No evidence for oxygen secretion was found, and the combination of 6 days incarceration and the loss of an artery was heroic. To obtain more data, Barcroft organized an expedition to Cerro de Pasco, Peru, altitude 4,300 m, that included investigators from both Cambridge, UK and Harvard. Again oxygen secretion was ruled out. The protocol included neuropsychometric measurements, and Barcroft famously concluded that all dwellers at high altitude are persons of impaired physical and mental powers, an assertion that has been hotly debated. Another colorful experiment in a low-pressure chamber involved reducing the pressure below that at the summit of Mt. Everest but giving the subjects 100% oxygen to breathe while exercising as a climber would on Everest. The conclusion was that it would be possible to reach the summit while breathing 100% oxygen. Barcroft was exceptional for his self-experimentation under hazardous conditions.

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

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    Amry Daulat Gultom

    2016-07-01

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

  6. HIGH-ALTITUDE ILLNESS

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    Dwitya Elvira

    2015-05-01

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

  7. Adaptation to High Altitude

    OpenAIRE

    1984-01-01

    Hypoxia is inconsequential for physiologically fit persons below an effective altitude of 2640 metres. At higher altitudes, the adaptation is brought about by four main factors, viz., hyperventilation, increased diffusion of oxygen across alveolar membrane, erythrocythemia and maintenance of body hydration. Carbon dioxide sensitivity is markedly elevated at high altitude, both in sojourners and acclimatized low-landers. The greater pulmonary diffusing capacity observed in high altitude native...

  8. Adaptation to High Altitude

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    H. S. Nayar

    1984-10-01

    Full Text Available Hypoxia is inconsequential for physiologically fit persons below an effective altitude of 2640 metres. At higher altitudes, the adaptation is brought about by four main factors, viz., hyperventilation, increased diffusion of oxygen across alveolar membrane, erythrocythemia and maintenance of body hydration. Carbon dioxide sensitivity is markedly elevated at high altitude, both in sojourners and acclimatized low-landers. The greater pulmonary diffusing capacity observed in high altitude natives is well documented. RBC count, haemoglobin and haematocrit increase whereas arterial oxyhaemoglobin saturation percentage decreases at high altitude. Diuretics (Furosemide have no role in adaptation to high altitude and adequate body hydration must be maintained.The ultimate adaptive mechanisms occur at tissue level which facilitate the diffusion of oxygen from blood to tissue and its utilization. The work capacity decreases at high altitude and a relationship between load carried and speed of marching has been determined at various altitudes. Although altitude has an adverse effect on process of cold acclimatization, yet it is possible to induce cold acclimatization by exposing subjects to a temperature of 0° to -5°C for a period of three hours daily for three weeks. The caloric requirements increase at high altitudes and are 4,286 K Cal and 4,380 K Cal at 13000 feet (3950 m and 17000 feet (5170 m, respectively.

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

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    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.

  10. High Altitude Cerebral Edema

    Science.gov (United States)

    1986-03-01

    such enzyme inhibition would favor the creation of a metabolic acidosis to offset the hypoxic respiratory alkalosis of high altitude hyperventilation...that some of their symptoms might be due to the early respiratory alkalosis seen upon arrival at high altitude. Unfortunately 23 out of the 30 subjects...i I Hamilton-16 was negative in all cases and normal respiratory excursions were seen. CSF chemistries and cell counts were normal. Houston and

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

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    Chun Guo

    2015-12-01

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

  12. High Altitude and Heart

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    Murat Yalcin

    2011-04-01

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

  13. Study of high-altitude radar altimeter model accuracy and SITAN performance using HAAFT data

    Energy Technology Data Exchange (ETDEWEB)

    Shieves, T.C.; Callahan, M.W.

    1979-07-01

    Radar altimetry data, inertial navigation data, and scoring data were collected under the HAAFT program by Martin Marietta Corporation for the United States Air Force over several areas in the western United States at altitudes ranging from 3 to 20 km. The study reported here uses the HAAFT data in conjunction with Defense Mapping Agency (DMA) topographic data to evaluate the accuracy of a high-altitude pulsed-radar altimeter model and the resulting performance of the terrain-aided guidance concept SITAN. Previous SITAN flight tests at low altitudes (less than 1500 m AGL) have demonstrated 6-20 m CEP. The high-altitude flight test data analyzed herein show a SITAN CEP of 120 m. The radar altimeter model was required to achieve this performance includes the effects of the internal track loop, AGC loop, antenna beamwidth, and the terrain radar cross section and provided a factor of 6 improvement over simple nadir ground clearance for rough terrain. It is postulated that high-altitude CEP could be reduced to 50 m or less if an altimeter were designed specifically for high-altitude terrain sensing.

  14. The structure of high altitude O+ energization and outflow: a case study

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    C. W. Carlson

    2004-07-01

    Full Text Available Multi-spacecraft observations from the CIS ion spectrometers on board the Cluster spacecraft have been used to study the structure of high-altitude oxygen ion energization and outflow. A case study taken from 12 April 2004 is discussed in more detail. In this case the spacecraft crossed the polar cap, mantle and high-altitude cusp region at altitudes between 4RE and 8RE and 2 of the spacecraft provided data. The oxygen ions were seen as a beam with narrow energy distribution, and increasing field-aligned velocity and temperature at higher altitude further in the upstream flow direction. The peak O+ energy was typically just above the highest energy of observed protons. The observed energies reached the upper limit of the CIS ion spectrometer, i.e. 38keV. Moment data from the spacecraft have been cross-correlated to determine cross-correlation coefficients, as well as the phase delay between the spacecraft. Structures in ion density, temperature and field-aligned flow appear to drift with the observed field-perpendicular drift. This, together with a velocity dispersion analysis, indicates that much of the structure can be explained by transverse heating well below the spacecraft. However, temperature isotropy and the particle flux as a function of field-aligned velocity are inconsistent with a single altitude Maxwellian source. Heating over extended altitude intervals, possibly all the way up to the observation point, seem consistent with the observations.

  15. Ear - blocked at high altitudes

    Science.gov (United States)

    High altitudes and blocked ears; Flying and blocked ears; Eustachian tube dysfunction - high altitude ... eustachian tube is a connection between the middle ear (the space deep to the eardrum) and the ...

  16. Brain Food at High Altitude.

    Science.gov (United States)

    Jain, Vishal

    2016-01-01

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

  17. Energy at high altitude.

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    Hill, N E; Stacey, M J; Woods, D R

    2011-03-01

    For the military doctor, an understanding of the metabolic effects of high altitude (HA) exposure is highly relevant. This review examines the acute metabolic challenge and subsequent changes in nutritional homeostasis that occur when troops deploy rapidly to HA. Key factors that impact on metabolism include the hypoxic-hypobaric environment, physical exercise and diet. Expected metabolic changes include augmentation of basal metabolic rate (BMR), decreased availability of oxygen in peripheral metabolic tissues, reduction in VO2 max, increased glucose dependency and lactate accumulation during exercise. The metabolic demands of exercise at HA are crucial. Equivalent activity requires greater effort and more energy than it does at sea level. Soldiers working at HA show high energy expenditure and this may exceed energy intake significantly. Energy intake at HA is affected adversely by reduced availability, reduced appetite and changes in endocrine parameters. Energy imbalance and loss of body water result in weight loss, which is extremely common at HA. Loss of fat predominates over loss of fat-free mass. This state resembles starvation and the preferential primary fuel source shifts from carbohydrate towards fat, reducing performance efficiency. However, these adverse effects can be mitigated by increasing energy intake in association with a high carbohydrate ration. Commanders must ensure that individuals are motivated, educated, strongly encouraged and empowered to meet their energy needs in order to maximise mission-effectiveness.

  18. High Altitude Dermatology

    Science.gov (United States)

    Singh, Lt. Col. G K

    2017-01-01

    Approximately, 140 million people worldwide live permanently at high altitudes (HAs) and approximately another 40 million people travel to HA area (HAA) every year for reasons of occupation, sports or recreation. In India, whole of Ladakh region, part of Northwest Kashmir, Northern part of Sikkim and Tenga valley of Arunachal are considered inhabited areas of HAA. The low quantity of oxygen, high exposure of ultraviolet (UV) light, very low humidity, extreme subzero temperature in winter, high wind velocity, make this region difficult for lowlanders as well as for tourists. Acute mountain sickness, HA pulmonary edema, HA cerebral edema, and thromboembolic conditions are known to occur in HA. However, enough knowledge has not been shared on dermatoses peculiar to this region. Xerosis, UV-related skin disorders (tanning, photomelanosis, acute and chronic sunburn, polymorphic light eruption, chronic actinic dermatitis, actinic cheilitis, etc.), cold injuries (frostbite, chilblains, acrocyanosis, erythrocyanosis, etc.) nail changes (koilonychias), airborne contact dermatitis, insect bite reaction, and skin carcinoma (basal cell carcinomas, squamous cell carcinomas, and also rarely malignant melanoma) are the dermatoses seen in HAAs. Early diagnosis and knowledge of HA dermatoses may prevent serious consequences of disease and improve the quality of life for the visitors as well as for native of the place. PMID:28216727

  19. High altitude dermatology

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    G K Singh

    2017-01-01

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

  20. Cardiovascular physiology at high altitude.

    Science.gov (United States)

    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.

  1. Effects of antioxidant vitamins on newborn and placental traits in gestations at high altitude: comparative study in high and low altitude native sheep.

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    Parraguez, Víctor H; Atlagich, Miljenko; Araneda, Oscar; García, Carlos; Muñoz, Andrés; De Los Reyes, Mónica; Urquieta, Bessie

    2011-01-01

    The present study evaluated the hypothesis that the effects of hypoxia on sheep pregnancies at high altitude (HA) are mediated by oxidative stress and that antioxidant vitamins may prevent these effects. Both HA native and newcomer ewes were maintained at an altitude of 3,589 m during mating and pregnancy. Control low altitude (LA) native ewes were maintained at sea level. Half of each group received daily oral supplements of vitamins C (500 mg) and E (350 IU) during mating and gestation. Near term, maternal plasma vitamin levels and oxidative stress biomarkers were measured. At delivery, lambs were weighed and measured, and placentas were recovered for macroscopic and microscopic evaluation. Vitamin concentrations in supplemented ewes were two- or threefold greater than in non-supplemented ewes. Plasma carbonyls and malondialdehyde in non-supplemented ewes were consistent with a state of oxidative stress, which was prevented by vitamin supplementation. Vitamin supplementation increased lamb birthweight and cotyledon number in both HA native and newcomer ewes, although placental weight and cotyledon surface were diminished. Placentas from vitamin-supplemented HA ewes were similar to those from ewes at sea level, making these placental traits (weight, number and diameter of cotyledons) similar to those from ewes at sea level. Vitamin supplementation had no effect on LA pregnancies. In conclusion, supplementation with vitamins C and E during pregnancy at HA prevents oxidative stress, improving pregnancy outcomes.

  2. The Yak genome database: an integrative database for studying yak biology and high-altitude adaption.

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    Hu, Quanjun; Ma, Tao; Wang, Kun; Xu, Ting; Liu, Jianquan; Qiu, Qiang

    2012-11-07

    The yak (Bos grunniens) is a long-haired bovine that lives at high altitudes and is an important source of milk, meat, fiber and fuel. The recent sequencing, assembly and annotation of its genome are expected to further our understanding of the means by which it has adapted to life at high altitudes and its ecologically important traits. The Yak Genome Database (YGD) is an internet-based resource that provides access to genomic sequence data and predicted functional information concerning the genes and proteins of Bos grunniens. The curated data stored in the YGD includes genome sequences, predicted genes and associated annotations, non-coding RNA sequences, transposable elements, single nucleotide variants, and three-way whole-genome alignments between human, cattle and yak. YGD offers useful searching and data mining tools, including the ability to search for genes by name or using function keywords as well as GBrowse genome browsers and/or BLAST servers, which can be used to visualize genome regions and identify similar sequences. Sequence data from the YGD can also be downloaded to perform local searches. A new yak genome database (YGD) has been developed to facilitate studies on high-altitude adaption and bovine genomics. The database will be continuously updated to incorporate new information such as transcriptome data and population resequencing data. The YGD can be accessed at http://me.lzu.edu.cn/yak.

  3. The Yak genome database: an integrative database for studying yak biology and high-altitude adaption

    Directory of Open Access Journals (Sweden)

    Hu Quanjun

    2012-11-01

    Full Text Available Abstract Background The yak (Bos grunniens is a long-haired bovine that lives at high altitudes and is an important source of milk, meat, fiber and fuel. The recent sequencing, assembly and annotation of its genome are expected to further our understanding of the means by which it has adapted to life at high altitudes and its ecologically important traits. Description The Yak Genome Database (YGD is an internet-based resource that provides access to genomic sequence data and predicted functional information concerning the genes and proteins of Bos grunniens. The curated data stored in the YGD includes genome sequences, predicted genes and associated annotations, non-coding RNA sequences, transposable elements, single nucleotide variants, and three-way whole-genome alignments between human, cattle and yak. YGD offers useful searching and data mining tools, including the ability to search for genes by name or using function keywords as well as GBrowse genome browsers and/or BLAST servers, which can be used to visualize genome regions and identify similar sequences. Sequence data from the YGD can also be downloaded to perform local searches. Conclusions A new yak genome database (YGD has been developed to facilitate studies on high-altitude adaption and bovine genomics. The database will be continuously updated to incorporate new information such as transcriptome data and population resequencing data. The YGD can be accessed at http://me.lzu.edu.cn/yak.

  4. High Altitude Pulmonary Edema Without Appropriate Action Progresses to Right Ventricular Strain: A Case Study.

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    Mills, Logan; Harper, Chris; Rozwadowski, Sophie; Imray, Chris

    2016-09-01

    Mills, Logan, Chris Harper, Sophie Rozwadowski, and Chris Imray. High altitude pulmonary edema without appropriate action progresses to right ventricular strain: A case study. High Alt Med Biol. 17:228-232, 2016.-A 24-year-old male developed high altitude pulmonary edema (HAPE) after three ascents to 4061 m over 3 days, sleeping each night at 2735 m. He complained of exertional dyspnea, dry cough, chest pain, fever, nausea, vertigo, and a severe frontal headache. Inappropriate continuation of ascent despite symptoms led to functional impairment and forced a return to the valley, but dyspnea persisted in addition to new orthopnea. Hospital admission showed hypoxemia, resting tachycardia, and systemic hypertension. ECG revealed right ventricular strain and a chest X-ray revealed right lower zone infiltrates. This case demonstrates that HAPE can develop in previously unaffected individuals given certain precipitating factors, and that in the presence of HAPE, prolonged exposure to altitude with exercise (or exertion) does not confer acclimatization with protective adaptations and that rest and descent are the appropriate actions. The case additionally demonstrates well-characterized right ventricular involvement.

  5. Developmental functional adaptation to high altitude: review.

    Science.gov (United States)

    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.

  6. Sleep at high altitude: guesses and facts.

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    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.

  7. Pupillary light reaction during high altitude exposure.

    Directory of Open Access Journals (Sweden)

    Maximilian Schultheiss

    Full Text Available PURPOSE: This study aimed to quantify the pupillary light reaction during high altitude exposure using the state of the art Compact Integrated Pupillograph (CIP and to investigate a potential correlation of altered pupil reaction with severity of acute mountain sickness (AMS. This work is related to the Tübingen High Altitude Ophthalmology (THAO study. METHODS: Parameters of pupil dynamics (initial diameter, amplitude, relative amplitude, latency, constriction velocity were quantified in 14 healthy volunteers at baseline (341 m and high altitude (4559 m over several days using the CIP. Scores of AMS, peripheral oxygen saturation and heart rate were assessed for respective correlations with pupil dynamics. For statistical analysis JMP was used and data are shown in terms of intra-individual normalized values (value during exposure/value at baseline and the 95% confidence interval for each time point. RESULTS: During high altitude exposure the initial diameter size was significantly reduced (p<0.05. In contrast, the amplitude, the relative amplitude and the contraction velocity of the light reaction were significantly increased (p<0.05 on all days measured at high altitude. The latency did not show any significant differences at high altitude compared to baseline recordings. Changes in pupil parameters did not correlate with scores of AMS. CONCLUSIONS: Key parameters of the pupillary light reaction are significantly altered at high altitude. We hypothesize that high altitude hypoxia itself as well as known side effects of high altitude exposure such as fatigue or exhaustion after ascent may account for an altered pupillogram. Interestingly, none of these changes are related to AMS.

  8. Pupillary Light Reaction during High Altitude Exposure

    Science.gov (United States)

    Schatz, Andreas; Wilhelm, Barbara; Peters, Tobias; Fischer, M. Dominik; Zrenner, Eberhart; Bartz-Schmidt, Karl U.; Gekeler, Florian; Willmann, Gabriel

    2014-01-01

    Purpose This study aimed to quantify the pupillary light reaction during high altitude exposure using the state of the art Compact Integrated Pupillograph (CIP) and to investigate a potential correlation of altered pupil reaction with severity of acute mountain sickness (AMS). This work is related to the Tübingen High Altitude Ophthalmology (THAO) study. Methods Parameters of pupil dynamics (initial diameter, amplitude, relative amplitude, latency, constriction velocity) were quantified in 14 healthy volunteers at baseline (341 m) and high altitude (4559 m) over several days using the CIP. Scores of AMS, peripheral oxygen saturation and heart rate were assessed for respective correlations with pupil dynamics. For statistical analysis JMP was used and data are shown in terms of intra-individual normalized values (value during exposure/value at baseline) and the 95% confidence interval for each time point. Results During high altitude exposure the initial diameter size was significantly reduced (p<0.05). In contrast, the amplitude, the relative amplitude and the contraction velocity of the light reaction were significantly increased (p<0.05) on all days measured at high altitude. The latency did not show any significant differences at high altitude compared to baseline recordings. Changes in pupil parameters did not correlate with scores of AMS. Conclusions Key parameters of the pupillary light reaction are significantly altered at high altitude. We hypothesize that high altitude hypoxia itself as well as known side effects of high altitude exposure such as fatigue or exhaustion after ascent may account for an altered pupillogram. Interestingly, none of these changes are related to AMS. PMID:24503770

  9. Cerebrovascular reactivity among native-raised high altitude residents: an fMRI study

    Directory of Open Access Journals (Sweden)

    Zhang Jiaxing

    2011-09-01

    Full Text Available Abstract Background The impact of long term residence on high altitude (HA on human brain has raised concern among researchers in recent years. This study investigated the cerebrovascular reactivity among native-born high altitude (HA residents as compared to native sea level (SL residents. The two groups were matched on the ancestral line, ages, gender ratios, and education levels. A visual cue guided maximum inspiration task with brief breath holding was performed by all the subjects while Blood-Oxygenation-Level-Dependent (BOLD functional Magnetic Resonance Imaging (fMRI data were acquired from them. Results Compared to SL controls, the HA group showed generally decreased cerebrovascular reactivity and longer delay in hemodynamic response. Clusters showing significant differences in the former aspect were located at the bilateral primary motor cortex, the right somatosensory association cortex, the right thalamus and the right caudate, the bilateral precuneus, the right cingulate gyrus and the right posterior cingulate cortex, as well as the left fusiform gyrus and the right lingual cortex; clusters showing significant differences in the latter aspect were located at the precuneus, the insula, the superior frontal and temporal gyrus, the somatosensory cortex (the postcentral gyrus and the cerebellar tonsil. Inspiratory reserve volume (IRV, which is an important aspect of pulmonary function, demonstrated significant correlation with the amount of BOLD signal change in multiple brain regions, particularly at the bilateral insula among the HA group. Conclusions Native-born HA residents generally showed reduced cerebrovascular reactivity as demonstrated in the hemodynamic response during a visual cue guided maximum inspiration task conducted with BOLD-fMRI. This effect was particularly manifested among brain regions that are typically involved in cerebral modulation of respiration.

  10. Risk prediction score for severe high altitude illness: a cohort study.

    Directory of Open Access Journals (Sweden)

    Florence Canouï-Poitrine

    Full Text Available Risk prediction of acute mountain sickness, high altitude (HA pulmonary or cerebral edema is currently based on clinical assessment. Our objective was to develop a risk prediction score of Severe High Altitude Illness (SHAI combining clinical and physiological factors. Study population was 1017 sea-level subjects who performed a hypoxia exercise test before a stay at HA. The outcome was the occurrence of SHAI during HA exposure. Two scores were built, according to the presence (PRE, n = 537 or absence (ABS, n = 480 of previous experience at HA, using multivariate logistic regression. Calibration was evaluated by Hosmer-Lemeshow chisquare test and discrimination by Area Under ROC Curve (AUC and Net Reclassification Index (NRI.The score was a linear combination of history of SHAI, ventilatory and cardiac response to hypoxia at exercise, speed of ascent, desaturation during hypoxic exercise, history of migraine, geographical location, female sex, age under 46 and regular physical activity. In the PRE/ABS groups, the score ranged from 0 to 12/10, a cut-off of 5/5.5 gave a sensitivity of 87%/87% and a specificity of 82%/73%. Adding physiological variables via the hypoxic exercise test improved the discrimination ability of the models: AUC increased by 7% to 0.91 (95%CI: 0.87-0.93 and 17% to 0.89 (95%CI: 0.85-0.91, NRI was 30% and 54% in the PRE and ABS groups respectively. A score computed with ten clinical, environmental and physiological factors accurately predicted the risk of SHAI in a large cohort of sea-level residents visiting HA regions.

  11. High altitude and the eye: a case controlled study in clinical ocular anthropometry of changes in the eye.

    Science.gov (United States)

    Bali, Jatinder; Chaudhary, K P; Thakur, Renu

    2005-01-01

    Tribal natives of two spatially separate districts of Lahaul-Spiti (mean altitude = 3300 m) and Kinnaur (mean altitude = 1,700 m) in the Himalayan state of Himachal Pradesh have lived for centuries as closed isolated groups, marrying within the local community up to the recent past. Studies on highland natives in the Andes have shown differences in chest diameters, lung volumes, hematocrit, and the like, in those living at high altitudes. We wanted to study whether stay at high altitude for generations confers any change in the ocular anthropometry. No study of this nature is available in the literature. We studied the ocular parameters using Snellen's charts, Standard Royal-Air-Force Rule, A-2,500 Sonomed A-Scan, Goldmann's aplanation tonometer, and S-7,000 Autorefractometer on 50 healthy volunteers at the Indira Gandhi Medical College Out Patient Department at Shimla (mean altitude = 2,100 m). Those living at higher altitudes in Lahaul-Spiti [LS] (n = 10) had significantly wider nose bridge width (p < 0.05); inter-inner canthal distance [IICD] (p < 0.05); inter-outer canthal distance [IOCD] (p < 0.05); and interpupillary distance [IPD] (p < 0.05) than the group living at Kinnaur (n = 40) at lower elevation. The LS group also had narrower palpebral fissure length in the vertical dimension (p = 0.05) and a lower IOP (p = 0.002) than the Kinnaur group. The axial length, lens thickness, and anterior chamber depth were comparable in the two groups. It appears that the eye and its adnexa respond to hypoxia, ultraviolet radiations, and persistent snow cover at high altitude by altering its anthropometry in a subtle but discernible manner. This was a hitherto unexplored area in the literature. Further studies to elucidate and substantiate the findings of the study are indicated.

  12. Cold Stress at High Altitudes

    Directory of Open Access Journals (Sweden)

    N. C. Majumdar

    1983-04-01

    Full Text Available The problem of cold at high altitudes has been analysed from a purely physical standpoint. It has been shown that Siple's Wind-Chill Index is not reliable because (i it does not make use of the well established principles governing the physical processes of heat transfer by convection and radiation, and (ii it assumes that the mean radiant temperature of the surroundings is the same as the ambient dry bulb temperature. A Cold Stress Index has been proposed which is likely to be a more reliable guide for assessing the climatic hazards of high altitude environments. The Index can be quickly estimated with the help of two nomograms devised for the purpose.

  13. Plasma proteomic study in patients with high altitude pulmonary edema (HAPE

    Directory of Open Access Journals (Sweden)

    Yong-jun LUO

    2012-01-01

    Full Text Available Objective  To investigate the differential expressions of protein in the plasma proteome in patients suffering from high altitude pulmonary edema (HAPE and their implications. Methods  The plasmas of six HAPE patients and six healthy controls were studied. The high-abundant proteins in the plasma were removed. The low-abundant proteins in the plasma/serum were segregated by 2-DE. MALDI-TOF/MS was adopted to measure the peptide fingerprints after the differential protein spots were digested by enzymes. Comparison and analysis were made in the GenBank. Results  The immunoglobulin K1 light chain, serum transferrin protein precursor, and α-trypsin inhibitor heavy chain-related protein expressions were upregulated in HAPE patients compared with the control group. However the human fibrin glue coagulation protein 3 was down-regulated. Conclusion  The differential expression of the above four proteins in the plasma of HAPE patients may be related to the occurrence of HAPE and can be used as the target point for the prediction of HAPE.

  14. An evolutionary frame of work to study physiological adaptation to high altitudes Un marco conceptual para estudiar adaptaciones fisiológicas a altas altitudes

    Directory of Open Access Journals (Sweden)

    ENRICO L. REZENDE

    2005-06-01

    Full Text Available How complex physiological systems evolve is one of the major questions in evolutionary physiology. For example, how traits interact at the physiological and genetic level, what are the roles of development and plasticity in Darwinian evolution, and eventually how physiological traits will evolve, remains poorly understood. In this article we summarize the current frame of work evolutionary physiologists are employing to study the evolution of physiological adaptations, as well as the role of developmental and reversible phenotypic plasticity in this context. We also highlight representative examples of how the integration of evolutionary and developmental physiology, concomitantly with the mechanistic understanding of physiological systems, can provide a deeper insight on how endothermic vertebrates could cope with reduced ambient temperatures and oxygen availability characteristic of high altitude environments. In this context, high altitude offers a unique system to study the evolution of physiological traits, and we believe much can be gained by integrating theoretical and empirical knowledge from evolutionary biology, such as life-history theory or the comparative method, with the mechanistic understanding of physiological processesUna de las preguntas más importantes en fisiología evolutiva es como evolucionan los sistemas fisiológicos complejos. Por ejemplo, actualmente sabemos poco sobre la interacción entre varios rasgos a niveles genéticos y fisiológicos, sobre el papel de la plasticidad fenotípica durante distintas etapas del desarrollo y madurez para la evolución fisiológica dentro de un linaje. En este trabajo explicamos el marco conceptual ocupado por fisiólogos evolutivos en la actualidad para estudiar adaptaciones fisiológicas a nivel evolutivo y el papel de la plasticidad dentro de la evolución Darviniana. Citamos ejemplos de como la integración de la fisiología evolutiva y del desarrollo nos permitió un mayor

  15. High Altitude Cooking and Food Safety

    Science.gov (United States)

    ... Standard Forms FSIS United States Department of Agriculture Food Safety and Inspection Service About FSIS District Offices Careers ... 286) Actions ${title} Loading... High Altitude Cooking and Food Safety What is considered a high altitude? How is ...

  16. Prevalence of COPD in five Colombian cities situated at low, medium, and high altitude (PREPOCOL study).

    Science.gov (United States)

    Caballero, Andrés; Torres-Duque, Carlos A; Jaramillo, Claudia; Bolívar, Fabio; Sanabria, Fernando; Osorio, Patricia; Orduz, Carlos; Guevara, Diana P; Maldonado, Darío

    2008-02-01

    The prevalence of COPD in Colombia is unknown. This study aimed to investigate COPD prevalence in five Colombian cities and measure the association between COPD and altitude. A cross-sectional design and a random, multistage, cluster-sampling strategy were used to provide representative samples of adults aged >or= 40 years. Each participant was interviewed (validated Spanish version of the Ferris Respiratory Questionnaire) and performed spirometry before and after 200 microg of inhaled salbutamol, using a portable spirometer according to American Thoracic Society recommendations. COPD definitions were as follows: (1) spirometric: fixed ratio (primary definition): FEV1/FVC or= 3 months every year during >or= 2 consecutive years (chronic bronchitis). Analysis was performed using statistical software. A total of 5,539 orsubjects were included. The overall COPD prevalence using the primary definition (spirometric) was 8.9%, ranging from 6.2% in Barranquilla to 13.5% in Medellín. The prevalence measured by the spirometric definition was higher than medical (2.8%) and clinical (3.2%) definitions. After the logistic regression analysis, the factors related with COPD were age >or= 60 years, male gender, history of tuberculosis, smoking, wood smoke exposure >or= 10 years, and very low education level. There was a nonsignificant tendency toward larger prevalence with higher altitude. COPD is an important health burden in Colombia. Additional studies are needed to establish the real influence of altitude on COPD prevalence.

  17. Sleep of Andean high altitude natives.

    Science.gov (United States)

    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.

  18. Studies on monitoring hemodynamics and oxygen dynamics of adult respiratory distress syndrome secondary to high altitude pulmonary edema

    Institute of Scientific and Technical Information of China (English)

    Ma Siqing; Wu Tianyi; Cheng Qiang; Li Pei; Bian Huiping

    2013-01-01

    To study monitoring hemodynamics and oxygen dynamics of adult respiratory distress syndrome (ARDS)secondary to high altitude pulmonary edema (HAPE),we performed clinic and laboratory studies in 8 patients who preliminarily developed high altitude cerebral edema (HACE) and then ARDS occurred at an altitude of 4500 m.After an initial emergency treatment on high mountains,all the patients were rapidly transported to a hospital at a lower altitude of 2808 m.The right cardiac catheterizations were carried out within 5 h after hospitalized.The monitoring hemodynamics and oxygen dynamics were studied via a thermodilution Swan-Gaze catheter.The results showed that before treatments at the beginning of monitoring,there presented a significant pulmonary artery hypertension with a decreased cardiac function,and a lower oxygen metabolism in all the 8 patients.However,after some effective treatments,including mechanical ventilation and using dexamethasone,furosemide,etc,four days later the result of a repeated monitoring showed that their pulmonary artery pressure had been decreased with an improved cardiac function with all the oxygen metabolic indexes increased significantly.Our studies suggested that performing monitoring hemodynamics in patients with ARDS secondary to HAPE will define the clinical therapeutic measures which will benefit the outcome.

  19. Oxygen ion energization observed at high altitudes

    Directory of Open Access Journals (Sweden)

    M. Waara

    2010-04-01

    Full Text Available We present a case study of significant heating (up to 8 keV perpendicular to the geomagnetic field of outflowing oxygen ions at high altitude (12 RE above the polar cap. The shape of the distribution functions indicates that most of the heating occurs locally (within 0.2–0.4 RE in altitude. This is a clear example of local ion energization at much higher altitude than usually reported. In contrast to many events at lower altitudes, it is not likely that the locally observed wave fields can cause the observed ion energization. Also, it is not likely that the ions have drifted from some nearby energization region to the point of observation. This suggests that additional fundamentally different ion energization mechanisms are present at high altitudes. One possibility is that the magnetic moment of the ions is not conserved, resulting in slower outflow velocities and longer time for ion energization.

  20. Adaptive modulation of adult brain gray and white matter to high altitude: structural MRI studies.

    Directory of Open Access Journals (Sweden)

    Jiaxing Zhang

    Full Text Available The aim of this study was to investigate brain structural alterations in adult immigrants who adapted to high altitude (HA. Voxel-based morphometry analysis of gray matter (GM volumes, surface-based analysis of cortical thickness, and Tract-Based Spatial Statistics analysis of white matter fractional anisotropy (FA based on MRI images were conducted on 16 adults (20-22 years who immigrated to the Qinghai-Tibet Plateau (2300-4400 m for 2 years. They had no chronic mountain sickness. Control group consisted of 16 matched sea level subjects. A battery of neuropsychological tests was also conducted. HA immigrants showed significantly decreased GM volumes in the right postcentral gyrus and right superior frontal gyrus, and increased GM volumes in the right middle frontal gyrus, right parahippocampal gyrus, right inferior and middle temporal gyri, bilateral inferior ventral pons, and right cerebellum crus1. While there was some divergence in the left hemisphere, surface-based patterns of GM changes in the right hemisphere resembled those seen for VBM analysis. FA changes were observed in multiple WM tracts. HA immigrants showed significant impairment in pulmonary function, increase in reaction time, and deficit in mental rotation. Parahippocampal and middle frontal GM volumes correlated with vital capacity. Superior frontal GM volume correlated with mental rotation and postcentral GM correlated with reaction time. Paracentral lobule and frontal FA correlated with mental rotation reaction time. There might be structural modifications occurred in the adult immigrants during adaptation to HA. The changes in GM may be related to impaired respiratory function and psychological deficits.

  1. High-altitude physiology: lessons from Tibet

    Science.gov (United States)

    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 (Pcardiac 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].

  2. Breathing and sleep at high altitude.

    Science.gov (United States)

    Ainslie, Philip N; Lucas, Samuel J E; Burgess, Keith R

    2013-09-15

    We provide an updated review on the current understanding of breathing and sleep at high altitude in humans. We conclude that: (1) progressive changes in pH initiated by the respiratory alkalosis do not underlie early (48 h), complex cellular and neurochemical re-organization occurs both in the peripheral chemoreceptors as well as within the central nervous system. The latter is likely influenced by central acid-base changes secondary to the extent of the initial respiratory responses to initial exposure to high altitude; (3) sleep at high altitude is disturbed by various factors, but principally by periodic breathing; (4) the extent of periodic breathing during sleep at altitude intensifies with duration and severity of exposure; (5) complex interactions between hypoxic-induced enhancement in peripheral and central chemoreflexes and cerebral blood flow--leading to higher loop gain and breathing instability--underpin this development of periodic breathing during sleep; (6) because periodic breathing may elevate rather than reduce mean SaO2 during sleep, this may represent an adaptive rather than maladaptive response; (7) although oral acetazolamide is an effective means to reduce periodic breathing by 50-80%, recent studies using positive airway pressure devices to increase dead space, hyponotics and theophylline are emerging but appear less practical and effective compared to acetazolamide. Finally, we suggest avenues for future research, and discuss implications for understanding sleep pathology.

  3. Estimation of high altitude Martian dust parameters

    Science.gov (United States)

    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.

  4. 1962 Satellite High Altitude Radiation Belt Database

    Science.gov (United States)

    2014-03-01

    TR-14-18 1962 Satellite High Altitude Radiation Belt Database Approved for public release; distribution is unlimited. March...the Status of the High Altitude Nuclear Explosion (HANE) Trapped Radiation Belt Database”, AFRL-VS-PS-TR- 2006-1079, Air Force Research Laboratory...Roth, B., “Blue Ribbon Panel and Support Work Assessing the Status of the High Altitude Nuclear Explosion (HANE) Trapped Radiation Belt Database

  5. Economy of Adaptation to High Altitude

    Institute of Scientific and Technical Information of China (English)

    Jean-Paul Richalet

    2004-01-01

    @@ The international meeting that will be held in Xining and Lhasa in August 2004 will be a wonderful occasion to share facts and concepts dealing with adaptation to high altitude. Life at high altitude is a challenge for thousands of animal species and millions of humans residing or visiting high altitude regions of the world. To try to understand the physiological mechanisms involved in the adaptation processes to high altitude hypoxia, it is convenient to start by defining what is "extreme" from a biological point of view.

  6. Aspirated Compressors for High Altitude Engines Project

    Data.gov (United States)

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

  7. X-Band Radar for Studies of Tropical Storms from High Altitude UAV Platform

    Science.gov (United States)

    Rodriquez, Shannon; Heymsfield, Gerald; Li, Lihua; Bradley, Damon

    2007-01-01

    The increased role of unmanned aerial vehicles (UAV) in NASA's suborbital program has created a strong interest in the development of instruments with new capabilities, more compact sizes and reduced weights than the instruments currently operated on manned aircrafts. There is a strong demand and tremendous potential for using high altitude UAV (HUAV) to carry weather radars for measurements of reflectivity and wind fields from tropical storms. Tropical storm genesis frequently occurs in ocean regions that are inaccessible to piloted aircraft due to the long off shore range and the required periods of time to gather significant data. Important factors of interest for the study of hurricane genesis include surface winds, profiled winds, sea surface temperatures, precipitation, and boundary layer conditions. Current satellite precipitation and surface wind sensors have resolutions that are too large and revisit times that are too infrequent to study this problem. Furthermore, none of the spaceborne sensors measure winds within the storm itself. A dual beam X-band Doppler radar, UAV Radar (URAD), is under development at the NASA Goddard Space Flight Center for the study of tropical storms from HUAV platforms, such as a Global Hawk. X-band is the most desirable frequency for airborne weather radars since these can be built in a relatively compact size using off-the-shelf components which cost significantly less than other higher frequency radars. Furthermore, X-band radars provide good sensitivity with tolerable attenuation in storms. The low-cost and light-weight URAD will provide new capabilities for studying hurricane genesis by analyzing the vertical structure of tropical cyclones as well as 3D reflectivity and wind fields in clouds. It will enable us to measure both the 3D precipitation structure and surface winds by using two antenna beams: fixed nadir and conical scanning each produced by its associated subsystem. The nadir subsystem is a magnetron based radar

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

    Science.gov (United States)

    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.

  9. Wave particle interactions in the high-altitude polar cusp: a Cluster case study

    Directory of Open Access Journals (Sweden)

    B. Grison

    2005-12-01

    Full Text Available On 23 March 2002, the four Cluster spacecraft crossed in close configuration (~100 km separation the high-altitude (10 RE cusp region. During a large part of the crossing, the STAFF and EFW instruments have detected strong electromagnetic wave activity at low frequencies, especially when intense field-aligned proton fluxes were detected by the CIS/HIA instrument. In all likelihood, such fluxes correspond to newly-reconnected field lines. A focus on one of these ion injection periods highlights the interaction between waves and protons. The wave activity has been investigated using the k-filtering technique. Experimental dispersion relations have been built in the plasma frame for the two most energetic wave modes. Results show that kinetic Alfvén waves dominate the electromagnetic wave spectrum up to 1 Hz (in the spacecraft frame. Above 0.8 Hz, intense Bernstein waves are also observed. The close simultaneity observed between the wave and particle events is discussed as an evidence for local wave generation. A mechanism based on current instabilities is consistent with the observations of the kinetic Alfvén waves. A weak ion heating along the recently-opened field lines is also suggested from the examination of the ion distribution functions. During an injection event, a large plasma convection motion, indicative of a reconnection site location, is shown to be consistent with the velocity perturbation induced by the large-scale Alfvén wave simultaneously detected.

  10. High-altitude adaptations in vertebrate hemoglobins

    DEFF Research Database (Denmark)

    Weber, Roy E.

    2007-01-01

    Vertebrates at high altitude are subjected to hypoxic conditions that challenge aerobic metabolism. O2 transport from the respiratory surfaces to tissues requires matching between the O2 loading and unloading tensions and theO2-affinity of blood, which is an integrated function of hemoglobin......, birds and ectothermic vertebrates at high altitude....

  11. High-altitude adaptations in vertebrate hemoglobins

    DEFF Research Database (Denmark)

    Weber, Roy E.

    2007-01-01

    Vertebrates at high altitude are subjected to hypoxic conditions that challenge aerobic metabolism. O2 transport from the respiratory surfaces to tissues requires matching between the O2 loading and unloading tensions and theO2-affinity of blood, which is an integrated function of hemoglobin......, birds and ectothermic vertebrates at high altitude....

  12. The High Altitude Water Cherenkov Observatory

    Science.gov (United States)

    Mostafa, Miguel; HAWC Collaboration

    2016-03-01

    The High Altitude Water Cherenkov (HAWC) Observatory is a continuously operated, wide field of view experiment comprised of an array of 300 water Cherenkov detectors (WCDs) to study transient and steady emission of TeV gamma and cosmic rays. Each 200000 l WCD is instrumented with 4 PMTs providing charge and timing information. The array covers ~22000 m2 at an altitude of 4100 m a.s.l. inside the Pico de Orizaba national park in Mexico. The high altitude, large active area, and optical isolation of the PMTs allows us to reliably estimate the energy and determine the arrival direction of gamma and cosmic rays with significant sensitivity over energies from several hundred GeV to a hundred TeV. Continuously observing 2 / 3 of the sky every 24 h, HAWC plays a significant role as a survey instrument for multi-wavelength studies. The performance of HAWC makes possible the detection of both transient and steady emissions, the study of diffuse emission and the measurement of the spectra of gamma-ray sources at TeV energies. HAWC is also sensitive to the emission from GRBs above 100 GeV. I will highlight the results from the first year of operation of the full HAWC array, and describe the ongoing site work to expand the array by a factor of 4 to explore the high energy range.

  13. The effect of high altitude on nasal nitric oxide levels.

    Science.gov (United States)

    Altundag, Aytug; Salihoglu, Murat; Cayonu, Melih; Cingi, Cemal; Tekeli, Hakan; Hummel, Thomas

    2014-09-01

    The aim of the present study was to investigate whether nasal nitric oxide (nNO) levels change in relation to high altitude in a natural setting where the weather conditions were favorable. The present study included 41 healthy volunteers without a history of acute rhinosinusitis within 3 weeks and nasal polyposis. The study group consisted of 31 males (76 %) and 10 females (24 %) and the mean age of the study population was 38 ± 10 years. The volunteers encamped for 2 days in a mountain village at an altitude of 1,500 m above sea level (masl) and proceeded to highlands at an altitude of 2,200 masl throughout the day. The measurements of nNO were done randomly, either first at the mountain village or at sea level. Each participant had nNO values both at sea level and at high altitude at the end of the study. The nNO values of sea level and high altitude were compared to investigate the effect of high altitude on nNO levels. The mean of average nNO measurements at the high altitude was 74.2 ± 41 parts-per-billion (ppb) and the mean of the measurements at sea level was 93.4 ± 45 ppb. The change in nNO depending on the altitude level was statistically significant (p high altitude even if the weather conditions were favorable, such as temperature, humidity, and wind.

  14. Theoretical and experimental studies of rectangular duct heat exchangers to be used in a high-altitude subsonic aircraft

    Science.gov (United States)

    Mathias, James Allen

    A unique need exists for heat exchangers that operate efficiently at an altitude of 85,000 feet. The application involves transferring heat to the low pressure ambient air at a low velocity that is in the laminar flow regime. Because it is desired that low pressure ambient air experience a small decrease in pressure, heat exchangers were examined with relatively short flowlengths and the boundary layers of the ambient air may be developing for a significant portion of the flowlength. These unique requirements of heat exchangers prompted an experimental study of compact heat exchangers made with relatively short rectangular fins that formed rectangular ducts. Compact heat exchangers made with rectangular fins were experimentally tested to determine the pressure drop of the air across the heat exchanger and the heat transfer to the air; the experiments were performed with air at Reynolds numbers between 100 and 1000. By placing the experimental apparatus in a chamber that was partially evacuated, experiments were also performed with air at a Reynolds number of approximately 250 at simulated elevated altitudes up to 83,000 feet. The results of the experiments performed at sea level and elevated altitudes compared very well. The results of the experiments that measured the pressure drop of the air determined the additional pressure drop caused by the developing boundary layers. An equation obtained from the data of the pressure drop measurements predicted the entrance length of the developing boundary layers. The Nusselt number of the air was calculated from the data of the heat transfer experiments. The Nusselt number significantly increased of the experiments performed with the boundary layers of the air developing for a significant portion of the rectangular duct. An equation was obtained that predicted the Nusselt number for compact heat exchangers with short flowlengths and with air at low Reynolds numbers. The equation that predicted the Nusselt number and the

  15. Cluster survey of the high-altitude cusp properties: a three-year statistical study

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    B. Lavraud

    2004-09-01

    Full Text Available The global characteristics of the high-altitude cusp and its surrounding regions are investigated using a three-year statistical survey based on data obtained by the Cluster spacecraft. The analysis involves an elaborate orbit-sampling methodology that uses a model field and takes into account the actual solar wind conditions and level of geomagnetic activity. The spatial distribution of the magnetic field and various plasma parameters in the vicinity of the low magnetic field exterior cusp are determined and it is found that: 1 The magnetic field distribution shows the presence of an intermediate region between the magnetosheath and the magnetosphere: the exterior cusp, 2 This region is characterized by the presence of dense plasma of magnetosheath origin; a comparison with the Tsyganenko (1996 magnetic field model shows that it is diamagnetic in nature, 3 The spatial distributions show that three distinct boundaries with the lobes, the dayside plasma sheet and the magnetosheath surround the exterior cusp, 4 The external boundary with the magnetosheath has a sharp bulk velocity gradient, as well as a density decrease and temperature increase as one goes from the magnetosheath to the exterior cusp, 5 While the two inner boundaries form a funnel, the external boundary shows no clear indentation, 6 The plasma and magnetic pressure distributions suggest that the exterior cusp is in equilibrium with its surroundings in a statistical sense, and 7 A preliminary analysis of the bulk flow distributions suggests that the exterior cusp is stagnant under northward IMF conditions but convective under southward IMF conditions.

  16. Neurophysiological Problems in Snow Bound High Altitude Areas

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    W. Selvamurthy

    1984-10-01

    Full Text Available A series of studies have been conducted to evaluate the neurophysiological responses in young healthy soldiers during acclimatization at 3,500m altitude in Western Himalayas. The responses of autonomic nervous system, electroencephalogram hypothalamic thermoregulatory efficiency, orthostatic tolerance, sleep profile and effects of sleep deprivation have been studied in fresh inductees during three to five weeks of acclimatization at high altitude and compared with those of one year acclimatized lowlanders and high altitude natives. Physiological significance of these neurophysiological responses in the process of altitude adaptation is discussed in the light of current knowledge in the field.

  17. Introductory address: lessons to be learned from high altitude.

    Science.gov (United States)

    Houston, C S

    1979-07-01

    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.

  18. High Altitude Clear Air Turbulence Project

    Data.gov (United States)

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

  19. Comparative study of enteric viruses, coliphages and indicator bacteria for evaluating water quality in a tropical high-altitude system

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    Mazari-Hiriart Marisa

    2009-10-01

    Full Text Available Abstract Background Bacteria used as indicators for pathogenic microorganisms in water are not considered adequate as enteric virus indicators. Surface water from a tropical high-altitude system located in Mexico City that receives rainwater, treated and non-treated wastewater used for irrigation, and groundwater used for drinking, was studied. Methods The presence of enterovirus, rotavirus, astrovirus, coliphage, coliform bacteria, and enterococci was determined during annual cycles in 2001 and 2002. Enteric viruses in concentrated water samples were detected by reverse transcriptase-polymerase chain reaction (RT-PCR. Coliphages were detected using the double agar layer method. Bacteria analyses of the water samples were carried out by membrane filtration. Results The presence of viruses and bacteria in the water used for irrigation showed no relationship between current bacterial indicator detection and viral presence. Coliphages showed strong association with indicator bacteria and enterovirus, but weak association with other enteric viruses. Enterovirus and rotavirus showed significant seasonal differences in water used for irrigation, although this was not clear for astrovirus. Conclusion Coliphages proved to be adequate faecal pollution indicators for the irrigation water studied. Viral presence in this tropical high-altitude system showed a similar trend to data previously reported for temperate zones.

  20. A randomly-controlled study on the cardiac function at the early stage of return to the plains after short-term exposure to high altitude.

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    Zhou, Qiquan; Yang, Shengyue; Luo, Yongjun; Qi, Yushu; Yan, Ziqiang; Shi, Zifu; Fan, Yong

    2012-01-01

    High altitude acclimatization and adaptation mechanisms have been well clarified, however, high altitude de-adaptation mechanism remains unclear. In this study, we conducted a controlled study on cardiac functions in 96 healthy young male who rapidly entered the high altitude (3700 m) and returned to the plains (1500 m) after 50 days. Ninety eight healthy male who remained at low altitude were recruited as control group. The mean pulmonary arterial pressure (mPAP), left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), cardiac function index (Tei index) were tested. Levels of serum creatine kinase isoform MB (CK-MB), lactate dehydrogenase isoenzyme-1 (LDH-1), endothelin-1 (ET-1), nitrogen oxide (NO), serum hypoxia-inducible factor-1α (HIF-1α), 8-iso-prostaglandin F(2α) (8-iso PGF(2α)), superoxide dismutase (SOD) and malonaldehyde (MDA) were measured at an altitude of 3700 m and 1500 m respectively. The results showed that after short-term exposure to high altitude mPAP and Tei index increased significantly, while LVEF and LVFS decreased significantly. These changes were positively correlated with altitude. On the 15(th) day after the subjects returned to low altitude, mPAP, LVEF and LVFS levels returned to the same level as those of the control subjects, but the Tei index in the returned subjects was still significantly higher than that in the control subjects (PLDH-1. These findings suggest that cardiac function de-adapts when returning to the plains after short-term exposure to high altitude and the function recovery takes a relatively long time.

  1. A randomly-controlled study on the cardiac function at the early stage of return to the plains after short-term exposure to high altitude.

    Directory of Open Access Journals (Sweden)

    Qiquan Zhou

    Full Text Available High altitude acclimatization and adaptation mechanisms have been well clarified, however, high altitude de-adaptation mechanism remains unclear. In this study, we conducted a controlled study on cardiac functions in 96 healthy young male who rapidly entered the high altitude (3700 m and returned to the plains (1500 m after 50 days. Ninety eight healthy male who remained at low altitude were recruited as control group. The mean pulmonary arterial pressure (mPAP, left ventricular ejection fraction (LVEF, left ventricular fraction shortening (LVFS, cardiac function index (Tei index were tested. Levels of serum creatine kinase isoform MB (CK-MB, lactate dehydrogenase isoenzyme-1 (LDH-1, endothelin-1 (ET-1, nitrogen oxide (NO, serum hypoxia-inducible factor-1α (HIF-1α, 8-iso-prostaglandin F(2α (8-iso PGF(2α, superoxide dismutase (SOD and malonaldehyde (MDA were measured at an altitude of 3700 m and 1500 m respectively. The results showed that after short-term exposure to high altitude mPAP and Tei index increased significantly, while LVEF and LVFS decreased significantly. These changes were positively correlated with altitude. On the 15(th day after the subjects returned to low altitude, mPAP, LVEF and LVFS levels returned to the same level as those of the control subjects, but the Tei index in the returned subjects was still significantly higher than that in the control subjects (P<0.01. We also found that changes in Tei index was positively correlated with mPAP, ET-1, HIF-1α and 8-iso PGF(2α levels, and negatively correlated with the level of NO, LVEF, LVFS, CK-MB and LDH-1. These findings suggest that cardiac function de-adapts when returning to the plains after short-term exposure to high altitude and the function recovery takes a relatively long time.

  2. Role of the altitude level on cerebral autoregulation in residents at high altitude.

    Science.gov (United States)

    Jansen, Gerard F A; Krins, Anne; Basnyat, Buddha; Odoom, Joseph A; Ince, Can

    2007-08-01

    Cerebral autoregulation is impaired in Himalayan high-altitude residents who live above 4,200 m. This study was undertaken to determine the altitude at which this impairment of autoregulation occurs. A second aim of the study was to test the hypothesis that administration of oxygen can reverse this impairment in autoregulation at high altitudes. In four groups of 10 Himalayan high-altitude dwellers residing at 1,330, 2,650, 3,440, and 4,243 m, arterial oxygen saturation (Sa(O(2))), blood pressure, and middle cerebral artery blood velocity were monitored during infusion of phenylephrine to determine static cerebral autoregulation. On the basis of these measurements, the cerebral autoregulation index (AI) was calculated. Normally, AI is between zero and 1. AI of 0 implies absent autoregulation, and AI of 1 implies intact autoregulation. At 1,330 m (Sa(O(2)) = 97%), 2,650 m (Sa(O(2)) = 96%), and 3,440 m (Sa(O(2)) = 93%), AI values (mean +/- SD) were, respectively, 0.63 +/- 0.27, 0.57 +/- 0.22, and 0.57 +/- 0.15. At 4,243 m (Sa(O(2)) = 88%), AI was 0.22 +/- 0.18 (P < 0.0005, compared with AI at the lower altitudes) and increased to 0.49 +/- 0.23 (P = 0.008, paired t-test) when oxygen was administered (Sa(O(2)) = 98%). In conclusion, high-altitude residents living at 4,243 m have almost total loss of cerebral autoregulation, which improved during oxygen administration. Those people living at 3,440 m and lower have still functioning cerebral autoregulation. This study showed that the altitude region between 3,440 and 4,243 m, marked by Sa(O(2)) in the high-altitude dwellers of 93% and 88%, is a transitional zone, above which cerebral autoregulation becomes critically impaired.

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

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    Sarah Eisen

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

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

    Science.gov (United States)

    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

  5. Early history of high-altitude physiology.

    Science.gov (United States)

    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.

  6. Increased oxidative stress following acute and chronic high altitude exposure.

    Science.gov (United States)

    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.

  7. Studies on strains of Trichoderma spp. from high altitude of Garhwal Himalayan region.

    Science.gov (United States)

    Joshi, B B; Vishwakarma, M P; Bahukhandi, D; Bhatt, R P

    2012-09-01

    Two species of Trichoderma i.e. T. harzianum and T. viride have been isolated from the soil samples collected from the higher altitude (2000-3500 m) of Garhwal Himalayan region in India. The two species were grown in Petri plates on TSM agar media and it was also observed that the optimum temperature and pH for Trichoderma growth was 30 degrees C and 5.5 respectively. When incubated on TSM agar medium at 4 degrees C, the fungus grew normally with heavy induced sporulation within three weeks of incubation. Induction of sporulation on exposure to low temperature appeared to be strategies for survival of these species in extreme cold environment temperature 4 to 5 degrees C. Antifungal activities of the two species of Trichoderma were demonstrated with phytopathogenic fungi in dual cultures. The antifungal metabolites produced by Trichoderma spp., diffusible as well as volatile, caused abnormalities in pathogenic fungi. Plant growth promotion of Trichoderma spp. was also shown through plant analysis in greenhouse.

  8. Aging, High Altitude, and Blood Pressure: A Complex Relationship.

    Science.gov (United States)

    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.

  9. Pulmonary Embolism Masquerading as High Altitude Pulmonary Edema at High Altitude.

    Science.gov (United States)

    Pandey, Prativa; Lohani, Benu; Murphy, Holly

    2016-12-01

    Pandey, Prativa, Benu Lohani, and Holly Murphy. Pulmonary embolism masquerading as high altitude pulmonary edema at high altitude. High Alt Med Biol. 17:353-358, 2016.-Pulmonary embolism (PE) at high altitude is a rare entity that can masquerade as or occur in conjunction with high altitude pulmonary edema (HAPE) and can complicate the diagnosis and management. When HAPE cases do not improve rapidly with descent, other diagnoses, including PE, ought to be considered. From 2013 to 2015, we identified eight cases of PE among 303 patients with initial diagnosis of HAPE. Upon further evaluation, five had deep vein thrombosis (DVT). One woman had a contraceptive ring and seven patients had no known thrombotic risks. PE can coexist with or mimic HAPE and should be considered in patients presenting with shortness of breath from high altitude regardless of thrombotic risk.

  10. A longitudinal study of cerebral blood flow under hypoxia at high altitude using 3D pseudo-continuous arterial spin labeling

    Science.gov (United States)

    Liu, Wenjia; Liu, Jie; Lou, Xin; Zheng, Dandan; Wu, Bing; Wang, Danny J. J.; Ma, Lin

    2017-01-01

    Changes in cerebral blood flow (CBF) may occur with acute exposure to high altitude; however, the CBF of the brain parenchyma has not been studied to date. In this study, identical magnetic resonance scans using arterial spin labeling (ASL) were performed to study the haemodynamic changes at both sea level and high altitude. We found that with acute exposure to high altitude, the CBF in acute mountain sickness (AMS) subjects was higher (P  0.05) compared with those at sea level. Moreover, magnetic resonance angiography in both AMS and non-AMS subjects showed a significant increase in the cross-sectional areas of the internal carotid, basilar, and middle cerebral arteries on the first day at high altitude. These findings support that AMS may be related to increased CBF rather than vasodilation; these results contradict most previous studies that reported no relationship between CBF changes and the occurrence of AMS. This discrepancy may be attributed to the use of ASL for CBF measurement at both sea level and high altitude in this study, which has substantial advantages over transcranial Doppler for the assessment of CBF. PMID:28240265

  11. Can High Altitude Influence Cytokines and Sleep?

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    Valdir de Aquino Lemos

    2013-01-01

    Full Text Available 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.

  12. Can High Altitude Influence Cytokines and Sleep?

    Science.gov (United States)

    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

  13. Oxidative stress in erythrocytes: a study on the effect of antioxidant mixtures during intermittent exposures to high altitude

    Science.gov (United States)

    Vani, R.; Shiva Shankar Reddy, C. S.; Asha Devi, S.

    2010-09-01

    The aim of our study was to compare and assess the effectiveness of antioxidant mixtures on the erythrocytes (RBC) of adult male albino rats (Wister) subjected to simulated intermittent high altitudes—5,100 m (AL1) and 6,700 m (AL2)—to induce oxidative stress (OS). To achieve our objective, we pre-supplemented four sets of animals with different antioxidant mixtures [vitamin E (vit.E; 50 IU/kg BW), vitamin C (vit.C; 400 mg/kg) and l-carnitine (400 mg/kg)] in different combinations [M1 (vit.E+vit.C), M2 (vit.C+carnitine), M3 (vit.E+carnitine) and M4 (vit.C+vit.E+carnitine)] for 30 days prior to as well during exposure to intermittent hypobaric hypoxia (IHH). Membrane instability, in terms of osmotic fragility and hemolysis, decreased in RBCs of supplemented animals. There was a significant increase in the activity of glutathione peroxidase in the RBCs of supplemented animals. We confirmed OS imposed by IHH with assays relating to lipid [thiobarbituric acid reactive substances (TBARS) and lipofuscin (LF)] and protein (carbonyl, PrC) oxidation, and found a positive correlation between PrC and hemolysis, with a decrease in both upon supplementation with M3 and M4 mixtures. Fluorescence microscopic observation showed a maximum decrease in the LF content in rats administered M4 and M1 compared to those on M2 and M3 mixtures at both altitudes. We suggest that multiple antioxidant fortifications are effective in overcoming increased OS experienced by RBCs at high altitudes.

  14. Station-keeping of a high-altitude balloon with electric propulsion and wireless power transmission: A concept study

    Science.gov (United States)

    van Wynsberghe, Erinn; Turak, Ayse

    2016-11-01

    A stable, ultra long-duration high-altitude balloon (HAB) platform which can maintain stationary position would represent a new paradigm for telecommunications and high-altitude observation and transmission services, with greatly reduced cost and complexity compared to existing technologies including satellites, telecom towers, and unmanned aerial vehicles (UAVs). This contribution proposes a lightweight superpressure balloon platform for deployment to an altitude of 25 km. Electrohydrodynamic (EHD) thrusters are presented to maintain position by overcoming stratospheric winds. Critical to maintaining position is a continual supply of electrical power to operate the on-board propulsion system. One viable solution is to deliver power wirelessly to a high-altitude craft from a ground-based transmitter. Microwave energy, not heavily attenuated by the atmosphere, can be provided remotely from a ground-based generator (magnetron, klystron, etc.) and steered electrically with an antenna array (phased array) at a designated frequency (such as 2.45 or 5.8 GHz). A rectifying antenna ("rectenna") on the bottom of the balloon converts waves into direct current for on-board use. Preliminary mission architecture, energy requirements, and safety concerns for a proposed system are presented along with recommended future work.

  15. Children's exercise capacity at high altitude in Tibet.

    Science.gov (United States)

    Bianba; Andersen, Lars Bo; Stigum, Hein; Ouzhuluobu; Bjertness, Espen

    2014-11-01

    Maximal oxygen uptake (exercise capacity) is a vital parameter in the evaluation of adaptation to high altitude, providing an index of the integrated function of the oxygen transport system. Previous studies of maximal oxygen uptake in population at high altitude have mainly focused on adults and adolescents, though data on children are uncommon. Maximal oxygen uptake can be measured directly, using an oxygen analyser, or indirectly through the development of equations for estimation from the maximal power output (W(max)). Such estimations and studies of the physiological aspects of children's capacity to work and live at different altitudes in Tibet ancestry were not reported previously, although differences similar to those seen in adults may be expected to occur. The present paper summarized the findings of studies on exercise capacity among children living at high altitude in Tibet.

  16. Prediction of future hydrological regimes in poorly gauged high altitude basins: the case study of the upper Indus, Pakistan

    Directory of Open Access Journals (Sweden)

    D. Bocchiola

    2011-04-01

    Full Text Available In the mountain regions of the Hindu Kush, Karakoram and Himalaya (HKH the "third polar ice cap" of our planet, glaciers play the role of "water towers" by providing significant amount of melt water, especially in the dry season, essential for agriculture, drinking purposes, and hydropower production. Recently, most glaciers in the HKH have been retreating and losing mass, mainly due to significant regional warming, thus calling for assessment of future water resources availability for populations down slope. However, hydrology of these high altitude catchments is poorly studied and little understood. Most such catchments are poorly gauged, thus posing major issues in flow prediction therein, and representing in facts typical grounds of application of PUB concepts, where simple and portable hydrological modeling based upon scarce data amount is necessary for water budget estimation, and prediction under climate change conditions. In this preliminarily study, future (2060 hydrological flows in a particular watershed (Shigar river at Shigar, ca. 7000 km2, nested within the upper Indus basin and fed by seasonal melt from major glaciers, are investigated.

    The study is carried out under the umbrella of the SHARE-Paprika project, aiming at evaluating the impact of climate change upon hydrology of the upper Indus river. We set up a minimal hydrological model, tuned against a short series of observed ground climatic data from a number of stations in the area, in situ measured ice ablation data, and remotely sensed snow cover data. The future, locally adjusted, precipitation and temperature fields for the reference decade 2050–2059 from CCSM3 model, available within the IPCC's panel, are then fed to the hydrological model. We adopt four different glaciers' cover scenarios, to test sensitivity to decreased glacierized areas. The projected flow duration curves, and some selected flow descriptors are evaluated. The uncertainty of the

  17. Prediction of future hydrological regimes in poorly gauged high altitude basins: the case study of the upper Indus, Pakistan

    Directory of Open Access Journals (Sweden)

    D. Bocchiola

    2011-07-01

    Full Text Available In the mountain regions of the Hindu Kush, Karakoram and Himalaya (HKH the "third polar ice cap" of our planet, glaciers play the role of "water towers" by providing significant amount of melt water, especially in the dry season, essential for agriculture, drinking purposes, and hydropower production. Recently, most glaciers in the HKH have been retreating and losing mass, mainly due to significant regional warming, thus calling for assessment of future water resources availability for populations down slope. However, hydrology of these high altitude catchments is poorly studied and little understood. Most such catchments are poorly gauged, thus posing major issues in flow prediction therein, and representing in fact typical grounds of application of PUB concepts, where simple and portable hydrological modeling based upon scarce data amount is necessary for water budget estimation, and prediction under climate change conditions. In this preliminarily study, future (2060 hydrological flows in a particular watershed (Shigar river at Shigar, ca. 7000 km2, nested within the upper Indus basin and fed by seasonal melt from major glaciers, are investigated.

    The study is carried out under the umbrella of the SHARE-Paprika project, aiming at evaluating the impact of climate change upon hydrology of the upper Indus river. We set up a minimal hydrological model, tuned against a short series of observed ground climatic data from a number of stations in the area, in situ measured ice ablation data, and remotely sensed snow cover data. The future, locally adjusted, precipitation and temperature fields for the reference decade 2050–2059 from CCSM3 model, available within the IPCC's panel, are then fed to the hydrological model. We adopt four different glaciers' cover scenarios, to test sensitivity to decreased glacierized areas. The projected flow duration curves, and some selected flow descriptors are evaluated. The uncertainty of

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

    Science.gov (United States)

    Qiu, Qiang; Zhang, Guojie; Ma, Tao; Qian, Wubin; Wang, Junyi; Ye, Zhiqiang; Cao, Changchang; Hu, Quanjun; Kim, Jaebum; Larkin, Denis M; Auvil, Loretta; Capitanu, Boris; Ma, Jian; Lewin, Harris A; Qian, Xiaoju; Lang, Yongshan; Zhou, Ran; Wang, Lizhong; Wang, Kun; Xia, Jinquan; Liao, Shengguang; Pan, Shengkai; Lu, Xu; Hou, Haolong; Wang, Yan; Zang, Xuetao; Yin, Ye; Ma, Hui; Zhang, Jian; Wang, Zhaofeng; Zhang, Yingmei; Zhang, Dawei; Yonezawa, Takahiro; Hasegawa, Masami; Zhong, Yang; Liu, Wenbin; Zhang, Yan; Huang, Zhiyong; Zhang, Shengxiang; Long, Ruijun; Yang, Huanming; Wang, Jian; Lenstra, Johannes A; Cooper, David N; Wu, Yi; Wang, Jun; Shi, Peng; Wang, Jian; Liu, Jianquan

    2012-07-01

    Domestic yaks (Bos grunniens) provide meat and other necessities for Tibetans living at high altitude on the Qinghai-Tibetan Plateau and in adjacent regions. Comparison between yak and the closely related low-altitude cattle (Bos taurus) is informative in studying animal adaptation to high altitude. Here, we present the draft genome sequence of a female domestic yak generated using Illumina-based technology at 65-fold coverage. Genomic comparisons between yak and cattle identify an expansion in yak of gene families related to sensory perception and energy metabolism, as well as an enrichment of protein domains involved in sensing the extracellular environment and hypoxic stress. Positively selected and rapidly evolving genes in the yak lineage are also found to be significantly enriched in functional categories and pathways related to hypoxia and nutrition metabolism. These findings may have important implications for understanding adaptation to high altitude in other animal species and for hypoxia-related diseases in humans.

  19. D-dimer is not elevated in asymptomatic high altitude climbers after descent to 5340 m: the Mount Everest Deep Venous Thrombosis Study (Ev-DVT).

    Science.gov (United States)

    Zafren, Ken; Feldman, Joanne; Becker, Robert J; Williams, Sarah R; Weiss, Eric A; Deloughery, Tom

    2011-01-01

    We performed this study to determine the prevalence of elevated D-dimer, a marker for deep venous thrombosis (DVT), in asymptomatic high altitude climbers. On-site personnel enrolled a convenience sample of climbers at Mt. Everest Base Camp (Nepal), elevation 5340 m (17,500 ft), during a single spring climbing season. Subjects were enrolled after descent to base camp from higher elevation. The subjects completed a questionnaire to evaluate their risk factors for DVT. We then performed a D-dimer test in asymptomatic individuals. If the D-dimer test was negative, DVT was considered ruled out. Ultrasound was available to perform lower-extremity compression ultrasounds to evaluate for DVT in case the D-dimer was positive. We enrolled 76 high altitude climbers. None had a positive D-dimer test. The absence of positive D-dimer tests suggests a low prevalence of DVT in asymptomatic high altitude climbers.

  20. A new Differential Optical Absorption Spectroscopy instrument to study atmospheric chemistry from a high-altitude unmanned aircraft

    Science.gov (United States)

    Stutz, Jochen; Werner, Bodo; Spolaor, Max; Scalone, Lisa; Festa, James; Tsai, Catalina; Cheung, Ross; Colosimo, Santo F.; Tricoli, Ugo; Raecke, Rasmus; Hossaini, Ryan; Chipperfield, Martyn P.; Feng, Wuhu; Gao, Ru-Shan; Hintsa, Eric J.; Elkins, James W.; Moore, Fred L.; Daube, Bruce; Pittman, Jasna; Wofsy, Steven; Pfeilsticker, Klaus

    2017-03-01

    Observations of atmospheric trace gases in the tropical upper troposphere (UT), tropical tropopause layer (TTL), and lower stratosphere (LS) require dedicated measurement platforms and instrumentation. Here we present a new limb-scanning Differential Optical Absorption Spectroscopy (DOAS) instrument developed for NASA's Global Hawk (GH) unmanned aerial system and deployed during the Airborne Tropical TRopopause EXperiment (ATTREX). The mini-DOAS system is designed for automatic operation under unpressurized and unheated conditions at 14-18 km altitude, collecting scattered sunlight in three wavelength windows: UV (301-387 nm), visible (410-525 nm), and near infrared (900-1700 nm). A telescope scanning unit allows selection of a viewing angle around the limb, as well as real-time correction of the aircraft pitch. Due to the high altitude, solar reference spectra are measured using diffusors and direct sunlight. The DOAS approach allows retrieval of slant column densities (SCDs) of O3, O4, NO2, and BrO with relative errors similar to other aircraft DOAS systems. Radiative transfer considerations show that the retrieval of trace gas mixing ratios from the observed SCD based on O4 observations, the most common approach for DOAS measurements, is inadequate for high-altitude observations. This is due to the frequent presence of low-altitude clouds, which shift the sensitivity of the O4 SCD into the lower atmosphere and make it highly dependent on cloud coverage. A newly developed technique that constrains the radiative transfer by comparing in situ and DOAS O3 observations overcomes this issue. Extensive sensitivity calculations show that the novel O3-scaling technique allows the retrieval of BrO and NO2 mixing ratios at high accuracies of 0.5 and 15 ppt, respectively. The BrO and NO2 mixing ratios and vertical profiles observed during ATTREX thus provide new insights into ozone and halogen chemistry in the UT, TTL, and LS.

  1. Cusp-like plasma in high altitudes: a statistical study of the width and location of the cusp from Magion-4

    Directory of Open Access Journals (Sweden)

    J. Mĕrka

    Full Text Available The width of the cusp region is an indicator of the strength of the merging process and the degree of opening of the magnetosphere. During three years, the Magion-4 satellite, as part of the Interball project, has collected a unique data set of cusp-like plasma observations in middle and high altitudes. For a comparison of high- and low-altitude cusp determination, we map our observations of cusp-like plasma along the magnetic field lines down to the Earth’s surface. We use the Tsyganenko and Stern 1996 model of the magnetospheric magnetic field for the mapping, taking actual solar wind and IMF parameters from the Wind observations. The footprint positions show substantial latitudinal dependence on the dipole tilt angle. We fit this dependence with a linear function and subtract this function from observed cusp position. This process allows us to study both statistical width and location of the inspected region as a function of the solar wind and IMF parameters. Our processing of the Magion-4 measurements shows that high-altitude regions occupied by the cusp-like plasma (cusp and cleft are projected onto a much broader area (in magnetic local time as well as in a latitude than that determined in low altitudes. The trends of the shift of the cusp position with changes in the IMF direction established by low-altitude observations have been confirmed.

    Key words. Magnetospheric physics (magnetopause, cusp and boundary layer; solar wind – magnetosphere interactions

  2. HAWC - The High Altitude Water Cherenkov Detector

    Science.gov (United States)

    Tepe, Andreas; HAWC Collaboration

    2012-07-01

    The high altitude water Cherenkov observatory (HAWC) is an instrument for the detection of high energy cosmic gamma-rays. Its predecessor Milagro has successfully proven that the water Cherenkov technology for gamma-ray astronomy is a useful technique. HAWC is currently under construction at Sierra Negra in Mexico at an altitude of 4100 m and will include several improvements compared to Milagro. Two complementary DAQ systems of the HAWC detector allow for the observation of a large fraction of the sky with a very high duty cycle and independent of environmental conditions. HAWC will observe the gamma-ray sky from about 100 GeV up to 100 TeV. Also the cosmic ray flux anisotropy on different angular length scales is object of HAWC science. Because of HAWC's large effective area and field of view, we describe its prospects to observe gamma-ray bursts (GRBs) as an example for transient sources.

  3. High altitude pulmonary edema among "Amarnath Yatris"

    Directory of Open Access Journals (Sweden)

    Parvaiz A Koul

    2013-01-01

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

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

    Science.gov (United States)

    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

  5. 'Ome' on the range: update on high-altitude acclimatization/adaptation and disease.

    Science.gov (United States)

    Luo, Yongjun; Wang, Yuxiao; Lu, Hongxiang; Gao, Yuqi

    2014-11-01

    The main physiological challenge in high-altitude plateau environments is hypoxia. When people living in a plain environment migrate to the plateau, they face the threat of hypoxia. Most people can acclimatize to high altitudes; the acclimatization process mainly consists of short-term hyperventilation and long-term compensation by increased oxygen uptake, transport, and use due to increased red blood cell mass, myoglobin, and mitochondria. If individuals cannot acclimatize to high altitude, they may suffer from a high-altitude disease, such as acute mountain disease (AMS), high-altitude pulmonary edema (HAPE), high-altitude cerebral edema (HACE) or chronic mountain sickness (CMS). Because some individuals are more susceptible to high altitude diseases than others, the incidence of these high-altitude diseases is variable and cannot be predicted. Studying "omes" using genomics, proteomics, metabolomics, transcriptomics, lipidomics, immunomics, glycomics and RNomics can help us understand the factors that mediate susceptibility to high altitude illnesses. Moreover, analysis of the "omes" using a systems biology approach may provide a greater understanding of high-altitude illness pathogenesis and improve the efficiency of the diagnosis and treatment of high-altitude illnesses in the future. Below, we summarize the current literature regarding the role of "omes" in high-altitude acclimatization/adaptation and disease and discuss key research gaps to better understand the contribution of "omes" to high-altitude illness susceptibility.

  6. Evaluating Coupled Human-Hydrologic Systems in High Altitude Regions: A Case Study of the Arun Watershed, Eastern Nepal

    Science.gov (United States)

    Voss, K.; Bookhagen, B.; Tague, C.; Lopez-Carr, D.

    2014-12-01

    The Himalaya exhibit dynamic ecological, hydrological, and climatic extremes that magnify the variability and extent of natural hazards, resulting in destruction to both physical and human landscapes. Coupled with poverty, these factors intensify local communities' vulnerability to climate change. This study highlights the Arun watershed in eastern Nepal as a case study to evaluate how local communities in high altitude regions are managing their water for domestic and agricultural needs while coping with extreme events, such as floods and landslides. Remotely-sensed precipitation, snowpack and glacial extent data from the past decade are combined with preliminary results from extensive field-based community surveys in the Arun watershed. The analysis of remotely-sensed data will describe seasonal trends in water availability, glacial lake growth, and the spatial variation of these trends within the basin. These hydrologic changes will be linked to the human survey analysis, which will provide an understanding of locals' perceptions of water challenges and the current water management strategies within the basin. Particular attention will be given to a comparison between the eastern and western tributaries of the Arun River, where the catchments are mainly rain-fed (eastern) versus glacial-fed (western). This contrast will highlight how different hydrologic scenarios evidenced from remote-sensing data motivate diverse human water management responses as defined in field surveys. A particular focus will be given to management decisions related to agriculture expansion and hydropower development. This synthesis of remote-sensing and social research methodologies provides a valuable perspective on coupled human-hydrologic systems.

  7. The High-Altitude Water Cherenkov Observatory

    Science.gov (United States)

    Mostafá, Miguel A.

    2014-10-01

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

  8. The high-altitude water Cherenkov Observatory

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

  9. The High Altitude Water Cherenkov (HAWC) Observatory

    Science.gov (United States)

    Springer, Wayne

    2014-06-01

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

  10. The High Altitude Water Cherenkov Observatory

    CERN Document Server

    ,

    2013-01-01

    The High Altitude Water Cherenkov (HAWC) observatory is a large field of view, continuously operated, TeV gamma-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 transient and steady emissions, to study the Galactic diffuse emission at TeV energies, and to measure or constrain the TeV spectra of GeV gamma-ray sources. In addition, HAWC will be the only ground-based instrument capable of detecting prompt emission from gamma-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 thirty WCDs (forming an array approximately the size of Milagro) were deployed in Summer...

  11. Reduced autonomic activity during stepwise exposure to high altitude

    NARCIS (Netherlands)

    Sevre, K; Bendz, B; Hanko, E; Nakstad, AR; Hauge, A; Kasin, JI; Lefrandt, JD; Smit, AJ; Eide, [No Value; Rostrup, M

    2001-01-01

    Several studies have shown increased sympathetic activity during acute exposure to hypobaric hypoxia. In a recent field study we found reduced plasma catecholamines during the first days after a stepwise ascent to high altitude. In the present study 14 subjects were exposed to a simulated ascent in

  12. Pulmonary embolism in young natives of high altitude

    Directory of Open Access Journals (Sweden)

    Sanjay Singhal

    2016-01-01

    Full Text Available 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.

  13. High altitude balloon experiments at IIA

    Science.gov (United States)

    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.

  14. High altitude headache occurs frequently among construction workers in Yushu

    Institute of Scientific and Technical Information of China (English)

    Wu Tianyi; Li Shuzhi; Jin Xinhui; Zhang Jianqing

    2013-01-01

    The aim was to measure the incidence of high altitude headache (HAH) and to determine clinical features,as well as the relation between acute mountain sickness (AMS) and HAH through a prospective study.We conducted a questionnaire-based study among construction workers in Yushu after a serious earthquake; they were under reconstruction using a structured questionnaire incorporating International Headache Society (IHS) and AMS Lake Louise Scoring System.A total of 608 workers were enrolled after their first ascent to altitudes of 3 750~4528 m.The results showed that 96 % reported at least 1 HAH(median 3.8,range from 1 to 10) in workers at a mean altitude of 4250 m.The magnitude of headache was divided as mild (38 %),moderate (44 %) and severe (18 %).This study indicates that HAH is the most common symptom of acute altitude exposure and closely correlated with altitude (r=0.165,p<0.001).However,52 % of headache was one of the main symptoms of AMS,while the other 48 % was the sole symptom of HAH.On the contrary we found that 2 % of AMS without headache,thus the "painless AMS" actually existed.The clinical features of HAH are presented,and the relationship between AMS and HAH is discussed.

  15. Lacustrine particle dynamics in high-altitude Estany Redó (Spain - a high resolution sediment trap study

    Directory of Open Access Journals (Sweden)

    Michael STURM

    2006-08-01

    Full Text Available Particle fluxes were measured from 2000 to 2001 with 3 integrating open traps (O-traps and a sequencing trap (S-trap in the 73-m deep, oligotrophic, high-mountain Estany (Lake Redó (2240 m a.s.l. over a period of 558 days. O-traps were deployed at 26, 46, and 66 m water depth to measure overall sedimentation rates, while the S-trap was deployed at 66 m water depth to detect dynamics of seasonal particle fluxes with a resolution of 4 days (during ice break-up, summer, ice formation to 21 days (during ice cover. Our results show a high degree of seasonal variability in particle dynamics. Total particle fluxes vary from almost zero to more than 600 mg m-2 d-1. The highest fluxes occur during short time windows after ice-break-up (minerogenic particles, during spring (planktonic biomass, and during fall overturn (chrysophycean cysts. Particle fluxes also differed markedly from year to year in absolute values (2000: 644 mg m-2 d-1, 2001: 370 mg m-2 d-1 as well as in average values (2000: 76 mg m-2 d-1, 2001: 44 mg m-2 d-1. Annual and seasonal meteorological changes and events have a clear influence on the lake system and on the amount and composition of particles. C/N ratios during April and May increased significantly from 2000 (6-14 to 2001 (>28, reflecting the more intense soil erosion and transport of terrestrial plant remains into the lake caused by heavy precipitation in 2001. Air temperature strongly influences the timing of the occurrence of the main bio-productivity peak. Strong wind events shorten the period of ice cover. Our investigation shows that sediment trap studies lasting more than one limnological cycle are useful in studying the effects of short-term meteorological changes and weather events on high mountain lakes. However, long-term particle flux measurements would be necessary to determine amplitudes of natural seasonal cycles and for the interpretation of the decadal-scale environmental changes occurring in such lakes.

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

    Science.gov (United States)

    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.

  17. Soldier at High Altitude: Problem & Preventive Measures

    Directory of Open Access Journals (Sweden)

    S.S Purkayastha

    2000-04-01

    Full Text Available Due to military and j trategic reasons, a large body of troops is being regularly dcployed in the snowbound areas through ut the Himalayan regions to guard Ihe Ironliers. Thc mountain environment at high 'allitude (HA consisls of several faclors alien lo plain dwellers, which evoke a series of physiological responses in human system. Some of the sea' level residents on induction to HA suffer from several unloward symploms of HA" ailmenls varying from mild-lo-severe degrees. Suddenexposure to HA is detrimental to physical and mental  performance of the low landers and  certain cases, may even lead to dreaded condition like high altitude pulmonary oedema (HAPO. These may make a man Jisturbed physically and mentally. So, there is a need lo prevent such hazards v(hich ispossible if the individual is aware of the problems and prevenlive measures ofHA ailments in advance, before going to HA for a safe and happy living there. Hence, a noble effort has been made to provide guidelines to create awareness about physical and physiological problems of life at HA and themethods of protection against its ill-effects for the soldiers, mountaineers and sojourners conducting scientific trials it HA. In th.:s revieJ, an attempt has been made to describe vital aspects of HA in a popular way, st~ing with its concept and various environmental factors which exert considerableettects on human body functions, heallh and performance on exposure to such environment, on the b¥is of a series of studies coitlucted at Ithe Defence Institute of Physiology & Allied Sciences, Delhi, oVer the years. The most important featurelof HA (3,000 m and above is hypoxia or deficiency ofoxygej1 in the body. Olher cnvironmental tactors are: scverc cold, high velocity wind, low rclalivc humidily, high solar radiatior, increased ultraviolet radialion and difficult terrain. These faclors are responsible for various HA cWtdc old syndromes, viz., acute mountain sickness, HAPO, dehydration,4

  18. THE HIGH ALTITUDE GAMMA RAY OBSERVATORY, HAWC

    Directory of Open Access Journals (Sweden)

    M. M. González

    2011-01-01

    Full Text Available El volcán Sierra Negra en Puebla, México fue seleccionado para albergar a HAWC (High Altitude Water Cherenkov, un observatorio de gran apertura (2Pi sr, único en el mundo, capaz de observar contínuamente el cielo a energías de 0.1 a 100 TeV. HAWC consiste en un arreglo a una altitud de 4100 m sobre el nivel del mar de 300 contenedores de 7.3 m de diámetro y 5 m de altura llenos de agua pura y sensores de luz que observan partículas sumamente energ´eticas provenientes de los eventos más violentos del universo y será 15 veces más sensible que su antecesor Milagro. Las aportaciones científicas de Milagro han demostrado las capacidades únicas de este tipo de observatorios. En este trabajo se presentará HAWC y se discutirá brevemente su caso científico y capacidades.

  19. Development of the High Altitude Student Platform

    Science.gov (United States)

    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.

  20. Effectiveness of Preacclimatization Strategies for High-Altitude Exposure

    Science.gov (United States)

    2013-01-01

    hypobaric conditions. IAE 15, 15 d of intermittent altitude exposure; IAE 7, 7 d of intermittent altitude expo- sure; NH (Sleep), Ambient normobaric hypoxia ...than those using norm(!)baric hypoxia (breathing, ង.9% ox-ygen). Key Words: hypobaric hypoxia , normobaric hypoxia , staging, acute mountain sickness...large decrements in endurance exercise performance occur when unacclimatized individuals rapidly ascend to high altitudes. Six altitude and hypoxia

  1. Hyperuricemia, hypertension, and proteinuria associated with high-altitude polycythemia.

    Science.gov (United States)

    Jefferson, J Ashley; Escudero, Elizabeth; Hurtado, Maria-Elena; Kelly, Jackeline Pando; Swenson, Erik R; Wener, Mark H; Burnier, Michel; Maillard, Marc; Schreiner, George F; Schoene, Robert B; Hurtado, Abdias; Johnson, Richard J

    2002-06-01

    Chronic exposure to high altitude is associated with the development of erythrocytosis, proteinuria, and, in some cases, hyperuricemia. We examined the relationship between high-altitude polycythemia and proteinuria and hyperuricemia in Cerro de Pasco, Peru (altitude, 4,300 m). We studied 25 adult men with hematocrits less than 65% and 27 subjects with excessive erythrocytosis (EE; hematocrit > 65%) living in Cerro de Pasco, Peru and compared them with 28 control subjects living in Lima, Peru (at sea level) and after 48 hours of exposure to high altitude. Serum urate levels were significantly elevated in patients with EE at altitude, and gout occurred in 4 of 27 of these subjects. Urate level strongly correlated with hematocrit (r = 0.71; P < 0.0001). Urate production (24-hour urine urate excretion and urine urate-creatinine ratio) was increased in this group compared with those at sea level. Fractional urate excretion was not increased, and fractional lithium excretion was reduced, in keeping with increased proximal reabsorption of filtrate. Significantly higher blood pressures and decreased renin levels in the EE group were in keeping with increased proximal sodium reabsorption. Serum urate levels correlated with mean blood pressure (r = 0.50; P < 0.0001). Significant proteinuria was more prevalent in the EE group despite normal renal function. Hyperuricemia is common in subjects living at high altitude and associated with EE, hypertension, and proteinuria. The increase in uric acid levels appears to be caused by increased urate generation secondary to systemic hypoxia, although a relative impairment in renal excretion also may contribute.

  2. Residential exposures to PM2.5 and CO in Cusco, a high-altitude city in the Peruvian Andes: a pilot study.

    Science.gov (United States)

    Pearce, John L; Aguilar-Villalobos, Manuel; Rathbun, Stephen L; Naeher, Luke P

    2009-01-01

    High-altitude populations using biofuels for household energy may be at health risk due to a combination of altitudinal stress and indoor exposures to biomass smoke. In this article, the authors measure indoor and outdoor breathing level concentrations of PM(2.5) and CO during periods of meal preparation in a convenience sample of homes above 3000 m in Cusco, Peru. From July 10 to 21, 2005, 237 measurements were taken during a pilot study at 41 residences. Results show the highest levels of PM(2.5) and CO occurred during the early morning in the kitchen when dung and wood were used. Additionally, findings suggest that residential biomass fuel combustion in Cusco results in elevated indoor PM(2.5) and CO exposure levels that are of potential human health concern, an issue that may be exacerbated by the physiological impact of living in a high-altitude environment.

  3. Isotopic and hydrogeochemical characterization of high-altitude karst aquifers in complex geological settings. The Ordesa and Monte Perdido National Park (Northern Spain) case study

    Energy Technology Data Exchange (ETDEWEB)

    Lambán, L.J., E-mail: javier.lamban@igme.es [Geological Survey of Spain (IGME) (Spain); Jódar, J., E-mail: jorge.jodar@upc.edu [Department of Geotechnical Engineering and Geosciences, Technical University of Catalonia (UPC), Barcelona (Spain); Custodio, E., E-mail: emilio.custodio@upc.edu [Department of Geotechnical Engineering and Geosciences, Technical University of Catalonia (UPC), Barcelona (Spain); Soler, A., E-mail: albertsoler@ub.edu [Grup de Mineralogia Aplicada i Medi Ambient, Departament Cristal lografia Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB) (Spain); Sapriza, G., E-mail: g.sapriza@usask.ca [Global Institute for Water Security, National Hydrology Research Centre (Canada); Soto, R., E-mail: r.soto@igme.es [Geological Survey of Spain (IGME) (Spain)

    2015-02-15

    The Ordesa and Monte Perdido National Park, located in the Southern Pyrenees, constitutes the highest karst system in Western Europe. No previous studies regarding its geochemical and isotopic groundwater characterization are available in this area. This work presents the results of field and sampling campaigns carried out between July 2007 and September 2013. The groundwater presents high calcium bicarbonate contents due to the occurrence of upper Cretaceous and lower Paleocene–Eocene carbonate materials in the studied area. Other relevant processes include dissolution of anhydrite and/or gypsum and incongruent dissolution of Mg-limestone and dolomite. The water stable isotopes (δ{sup 18}O, δ{sup 2}H) show that the oceanic fronts from the Atlantic Ocean are responsible for the high levels of precipitation. In autumn, winter, and spring, a deuterium excess is found in the recharge water, which could be related to local atmospheric transport of low-altitude snow sublimation vapour and its later condensation on the snow surface at higher altitude, where recharge is mostly produced. The recharge zones are mainly between 2500 m and 3200 m a.s.l. The tritium content of the water suggests short groundwater transit times. The isotopic composition of dissolved sulphate points to the existence of regional fluxes mixed with local discharge in some of the springs. This work highlights the major role played by the altitude difference between the recharge and discharge zones in controlling the chemistry and the vertical variability of the isotopic composition in high-altitude karst aquifers. - Highlights: • Environmental tracers are essential to study complex alpine karst aquifers. • The long presence of snow controls the deuterium excess in groundwater. • Seasonal δD content in springs depends on gap between recharge and discharge points. • The first hydrogeological characterization of the Ordesa National Park is presented. • Sulphate content in springs comes

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

    Science.gov (United States)

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

    2012-01-01

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

  5. Sleep apneas and high altitude newcomers.

    Science.gov (United States)

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

    Directory of Open Access Journals (Sweden)

    Shah NM

    2015-09-01

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

  7. Enhanced hepatic insulin signaling in the livers of high altitude native rats under basal conditions and in the livers of low altitude native rats under insulin stimulation: a mechanistic study.

    Science.gov (United States)

    Al Dera, Hussain; Eleawa, Samy M; Al-Hashem, Fahaid H; Mahzari, Moeber M; Hoja, Ibrahim; Al Khateeb, Mahmoud

    2017-07-01

    This study was designed to investigate the role of the liver in lowering fasting blood glucose levels (FBG) in rats native to high (HA) and low altitude (LA) areas. As compared with LA natives, besides the improved insulin and glucose tolerance, HA native rats had lower FBG, at least mediated by inhibition of hepatic gluconeogenesis and activation of glycogen synthesis. An effect that is mediated by the enhancement of hepatic insulin signaling mediated by the decreased phosphorylation of TSC induced inhibition of mTOR function. Such effect was independent of activation of AMPK nor stabilization of HIF1α, but most probably due to oxidative stress induced REDD1 expression. However, under insulin stimulation, and in spite of the less activated mTOR function in HA native rats, LA native rats had higher glycogen content and reduced levels of gluconeogenic enzymes with a more enhanced insulin signaling, mainly due to higher levels of p-IRS1 (tyr612).

  8. Body Structure and Respiratory Efficiency among High Altitude Himalayan Populations

    OpenAIRE

    2005-01-01

    To understand the morphological and physiological variations among the temporary and permanent residents of high altitude, this study was undertaken at Leh, Ladakh. It is situated at 3500 m (11500 feet) above sea level, the mean barometric pressure was 500 tors and air temperature varied from 2 °C to 20 °C. The highland Tibetans showed broadest chest and most developed musculature closely followed by Ladakhi Bods. These high altude natives also displayed significantly higher value of vital ca...

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Science.gov (United States)

    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.

  11. Solar electric energy supply at high altitude

    Energy Technology Data Exchange (ETDEWEB)

    Knaupp, W.; Mundschau, E. [Zentrum fur Sonnenenergie- und Wasserstoff-Forschung (ZSW), Ulm (Germany)

    2004-04-01

    Solar-hydrogen systems were analyzed regarding their usability as energy supply system for high altitude platforms. In a first step for an assessment of solar and photovoltaic resources near-ground spectral transmittances of atmosphere were extended with simplified height correction functions to achieve spectral irradiance descriptions versus atmospheric height up to 25 km. The influence of atmospheric height to different solar cell technologies regarding electrical performance was quantified at some examples for the aspect of spectral distribution with the help of the introduced spectral height factor. The main attention during analysis of the whole solar-hydrogen energy system was directed to characteristics of current or near term available technology. Specific power weight of photovoltaic system, electrolyzer, fuel cell and gas tanks and their dependence on operation mode and power range were assessed. A pre-design of a solar-hydrogen energy system was carried out for an airship (volume 580,000 m3) withstanding continuous wind speeds up to {approx} 130 km/h. The calculated coverage ratio of photovoltaic and load share of energy system mark the frame of usability. Depending on the airship size, shape and other external boundary conditions the total electrical energy demand could be covered by a solar-hydrogen energy system of current or near term technology for full year operation. However further investigations are necessary regarding e.g. further mass reductions. (author)

  12. Lens autofluorescence is not increased at high altitude

    DEFF Research Database (Denmark)

    Kessel, Line; Kofoed, Peter Kristian; Zubieta-Calleja, Gustavo

    2010-01-01

    PURPOSE: To study the relation between ambient environmental ultraviolet radiation exposure and lens fluorescence. METHODS: Non-invasive lens fluorometry measurements were compared in healthy Bolivian and Danish subjects. Background ultraviolet radiation was 4.5 times higher in Bolivia than...... in Denmark. RESULTS: No significant differences in lens fluorescence or transmittance were found between Bolivian and Danish volunteers. CONCLUSION: Age-corrected lens fluorescence and transmittance were comparable for healthy participants living at high altitude near the equator and healthy volunteers...

  13. Oxidative stress and the high altitude environment

    Directory of Open Access Journals (Sweden)

    Jakub Krzeszowiak

    2013-03-01

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

  14. Initial Feasibility Assessment of a High Altitude Long Endurance Airship

    Science.gov (United States)

    Colozza, Anthony; Dolce, James (Technical Monitor)

    2003-01-01

    A high altitude solar powered airship provides the ability to carry large payloads to high altitudes and remain on station for extended periods of time. This study examines the feasibility of this concept. Factors such as time of year, latitude, wind speeds and payload are considered in establishing the capabilities of a given size airship. East and West coast operation were evaluated. The key aspect to success of this type of airship is the design and operation of the propulsion and power system. A preliminary propulsion/power system design was produced based on a regenerative fuel cell energy storage system and solar photovoltaic array for energy production. A modular system design was chosen with four independent power/propulsion units utilized by the airship. Results on payload capacity and flight envelope (latitude and time of year) were produced for a range of airship sizes.

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

    CERN Document Server

    Carramiñana, Alberto

    2016-01-01

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

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

    Science.gov (United States)

    Carramiñana, Alberto

    2016-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Gorka Alkorta-Aranburu

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

  18. The University of Alberta High Altitude Balloon Program

    Science.gov (United States)

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

    2011-12-01

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

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

    Science.gov (United States)

    Luo, Yongjun; Yang, Xiaohong; Gao, Yuqi

    2013-08-01

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

  20. Blood-Brain Barrier Changes in High Altitude.

    Science.gov (United States)

    Lafuente, José V; Bermudez, Garazi; Camargo-Arce, Lorena; Bulnes, Susana

    2016-01-01

    Cerebral syndromes related to high-altitude exposure are becoming more frequent as the number of trips to high altitudes has increased in the last decade. The commonest symptom is headache, followed by acute mountain sickness (AMS) and high-altitude cerebral edema (HACE), which can be fatal. The pathophysiology of these syndromes is not fully understood. The classical "tight-fit hypothesis" posits that there are some anatomical variations that would obstruct the sinovenous outflow and worsen vasogenic edema and intracranial hypertension reactive to hypoxia. This could explain microhemorrhages seen in autopsies. However, recent magnetic resonance imaging studies have demonstrated some components of cytotoxic edema in HACE absent in AMS, suggesting a dysfunction in water balance at the cellular level. Currently, the "red-ox theory" supports trigemino-vascular system activation by free radicals formed after hypoxia and the consequent oxidative stress cascades. Apart from trigemino-vascular system activation, free radicals can also provoke membrane destabilisation mediated by lipid peroxidation, inflammation, and local hypoxia inducible factor-1α and vascular endothelial growth factor activation, resulting in gross blood-brain barrier (BBB) dysfunction. Besides alterations in endothelial cells such as increased pinocytotic vesicles and disassembly of interendothelial tight junction proteins, capillary permeability may also increase with subsequent swelling of astrocyte end-feet. In conclusion, although the pathophysiology of AMS and HACE is not completely understood, recent evidence proposes a multifactorial entity, with brain swelling and compromise of the BBB considered to play an important role. A fuller comprehension of these processes is crucial to reduce and prevent BBB alterations during high-altitude exposure.

  1. Contemporary sediment production and transfer in high-altitude glaciers

    Science.gov (United States)

    Owen, Lewis A.; Derbyshire, Edward; Scott, Christine H.

    2003-01-01

    The nature of fine-grained sediment production and transfer in high-altitude debris-covered glaciers was studied by examining the Rakhiot and Chungphar glaciers in the Nanga Parbat Himalaya, Northern Pakistan. Transport pathways, from the source areas to the glacier snout, were mapped and samples collected for particle size analysis and scanning electron microscopy. Positive down-glacier trends in sediment fining and increased weathering showed that debris transport in the supraglacial zone of these Himalayan glaciers is an important contributor to contemporary glacial sediment production, resulting in intense comminution that yields large volumes of fine sediment. These findings cast doubt on the traditional view that the basal traction zone of glaciers is the only major source of fine sediment production in glaciated environments, although that view may hold true for classic alpine glaciers that are at lower altitudes and, as a consequence, generally have less supraglacial debris cover. To test this hypothesis, the Glacier de Cheilon, in the Swiss Alps was also studied. This glacier did not exhibit such striking down-glacier trends in the particle size characteristics measured. It is thus suggested that a thick debris-cover may be an important source of fine-grained sediments on glaciers that occur in high-altitude environments.

  2. Accuracy of Handheld Blood Glucose Meters at High Altitude

    NARCIS (Netherlands)

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

    2010-01-01

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

  3. Sensitivity Analysis of Temperature Control Parameters and Study of the Simultaneous Cooling Zone during Dam Construction in High-Altitude Regions

    Directory of Open Access Journals (Sweden)

    Zhenhong Wang

    2015-01-01

    Full Text Available There are unprecedented difficulties in building concrete gravity dams in the high altitude province Tibet with problems induced by lack of experience and technologies and unique weather conditions, as well as the adoption of construction materials that are disadvantageous to temperature control and crack prevention. Based on the understandings of the mentioned problems and leveraging the need of building gravity dam in Tibet, 3D finite element method is used to study the temperature control and crack prevention of the dam during construction. The calculation under recommend temperature control measures and standards shows that the height and number of simultaneous cooling zone have the more obvious influencers on concrete stress; therefore, it is suggested to increase the height of simultaneous cooling zone to decrease the stress caused by temperature gradient of adjoin layers so as to raise the safety level of the whole project. The research methods and ideas used on this project have significant values and can be taken as references in similar projects in high altitude regions.

  4. Cognitive Changes during Prolonged Stay at High Altitude and Its Correlation with C-Reactive Protein.

    Directory of Open Access Journals (Sweden)

    Sheng Li Hu

    Full Text Available Hypersensitive C-reaction protein (hsCRP may be a risk factor for cognitive impairment resulting from Alzheimer's disease (AD, stroke, and vascular dementia. This study explored the correlation of peripheral blood hsCRP level with cognitive decline due to high altitude exposure. The study was conducted on 100 male military participants who had never been to high altitude. Cerebral oxygen saturation monitoring, event related potentials (P300, N200 detection, and neurocognitive assessment was performed and total hsCRP, interleukin-6 (IL-6, and homocysteine was estimated at 500 m altitude, 3650 m altitude, 3 day, 1, and 3 month post arriving at the base camp (4400 m, and 1 month after coming back to the 500 m altitude. High altitude increased brain oxygen saturation, prolonged P300 and N200 latencies, injured cognitive functions, and raised plasma hsCRP levels. But they all recovered in varying degrees at 1 and 3 month post arriving at the base camp (4400 m. P300 latencies and hsCRP levels were strongly correlated to cognitive performances. These results suggested that cognitive deterioration occurred during the acute period of exposure to high altitude and may recover probably owning to acclimatization after extended stay at high altitude. Plasma hsCRP is inversely correlated to neurological cognition and it may be a potential biomarker for the prediction of high altitude induced cognitive dysfunction.

  5. Cognitive Changes during Prolonged Stay at High Altitude and Its Correlation with C-Reactive Protein

    Science.gov (United States)

    Hu, Sheng Li; Xiong, Wei; Dai, Zhi Qiang; Zhao, Heng Li; Feng, Hua

    2016-01-01

    Hypersensitive C-reaction protein (hsCRP) may be a risk factor for cognitive impairment resulting from Alzheimer’s disease (AD), stroke, and vascular dementia. This study explored the correlation of peripheral blood hsCRP level with cognitive decline due to high altitude exposure. The study was conducted on 100 male military participants who had never been to high altitude. Cerebral oxygen saturation monitoring, event related potentials (P300, N200) detection, and neurocognitive assessment was performed and total hsCRP, interleukin-6 (IL-6), and homocysteine was estimated at 500m altitude, 3650m altitude, 3day, 1, and 3 month post arriving at the base camp (4400m), and 1 month after coming back to the 500m altitude. High altitude increased brain oxygen saturation, prolonged P300 and N200 latencies, injured cognitive functions, and raised plasma hsCRP levels. But they all recovered in varying degrees at 1 and 3 month post arriving at the base camp (4400m). P300 latencies and hsCRP levels were strongly correlated to cognitive performances. These results suggested that cognitive deterioration occurred during the acute period of exposure to high altitude and may recover probably owning to acclimatization after extended stay at high altitude. Plasma hsCRP is inversely correlated to neurological cognition and it may be a potential biomarker for the prediction of high altitude induced cognitive dysfunction. PMID:26731740

  6. Travel to High Altitude Following Solid Organ Transplantation.

    Science.gov (United States)

    Luks, Andrew M

    2016-09-01

    Luks, Andrew M. Clinician's corner: travel to high altitude following solid organ transplantation. High Alt Med Biol. 17:147-156, 2016.-As they regain active lifestyles following successful organ transplantation, transplant recipients may travel to high altitude for a variety of activities, including skiing, climbing, and trekking. This review is intended to provide information for medical providers who may encounter transplant patients seeking advice before planned high altitude travel or care for medical issues that develop during the actual sojourn. There is currently limited information in the literature about outcomes during high-altitude travel following solid organ transplantation, but the available evidence suggests that the physiologic responses to hypobaric hypoxia are comparable to those seen in nontransplanted individuals and well-selected transplant recipients with no evidence of organ rejection can tolerate ascents as high as 6200 m. All transplant recipients planning high-altitude travel should undergo pretravel assessment and counseling with an emphasis on the recognition, prevention, and treatment of altitude illness, as well as the importance of preventing infection and limiting sun exposure. Transplant recipients can use the standard medications for altitude illness prophylaxis and treatment, but the choice and dose of medication should take into account the patient's preexisting medication regimen and current renal function. With careful attention to these and other details, the healthy transplant recipient can safely experience the rewards of traveling in the mountains.

  7. DLR HABLEG- High Altitude Balloon Launched Experimental Glider

    Science.gov (United States)

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

    2015-09-01

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

  8. First scientific contributions from the High Altitude Water Cherenkov Observatory

    Science.gov (United States)

    León Vargas, H.; HAWC Collaboration

    2015-09-01

    The High Altitude Water Cherenkov Observatory (HAWC), located at the slopes of the volcanoes Sierra Negra and Pico de Orizaba in Mexico, was inaugurated on March 20, 2015. However, data taking started in August 2013 with a partially deployed observatory and since then the instrument has collected data as it got closer to its final configuration. HAWC is a ground based TeV gamma-ray observatory with a large field of view that will be used to study the Northern sky with high sensitivity. In this contribution we present some of the results obtained with the partially built instrument and the expected capabilities to detect different phenomena with the complete observatory.

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

    Science.gov (United States)

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

    2010-12-25

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

  10. Shilajit: A panacea for high-altitude problems.

    Science.gov (United States)

    Meena, Harsahay; Pandey, H K; Arya, M C; Ahmed, Zakwan

    2010-01-01

    High altitude problems like hypoxia, acute mountain sickness, high altitude cerebral edema, pulmonary edema, insomnia, tiredness, lethargy, lack of appetite, body pain, dementia, and depression may occur when a person or a soldier residing in a lower altitude ascends to high-altitude areas. These problems arise due to low atmospheric pressure, severe cold, high intensity of solar radiation, high wind velocity, and very high fluctuation of day and night temperatures in these regions. These problems may escalate rapidly and may sometimes become life-threatening. Shilajit is a herbomineral drug which is pale-brown to blackish-brown, is composed of a gummy exudate that oozes from the rocks of the Himalayas in the summer months. It contains humus, organic plant materials, and fulvic acid as the main carrier molecules. It actively takes part in the transportation of nutrients into deep tissues and helps to overcome tiredness, lethargy, and chronic fatigue. Shilajit improves the ability to handle high altitudinal stresses and stimulates the immune system. Thus, Shilajit can be given as a supplement to people ascending to high-altitude areas so that it can act as a "health rejuvenator" and help to overcome high-altitude related problems.

  11. Ataxia, acute mountain sickness, and high altitude cerebral edema

    Institute of Scientific and Technical Information of China (English)

    Wu Tianyi; Ma Siqing; Bian Huiping; Zhang Minming

    2013-01-01

    Previous investigations suggest that ataxia is common and often one of the most reliable warning signs of high altitude cerebral edema(HACE).The aim of this study was to investigate the diagnostic role of ataxia in acute mountain sickness (AMS) and HACE among mountain rescuers on the quake areas,and in approaching the relation between AMS and HACE.After the earthquake on April 14,2010,approximately 24080 lowland rescuers were rapidly transported from sea level or lowlands to the mountainous rescue sites at 3750 ~ 4568 m,and extremely hardly worked for an emergency treatment after arrival.Assessments of acute altitude illness on the quake areas were using the Lake Louise Scoring System.73 % of the rescuers were found to be developed AMS.The incidence of high altitude pulmonary edema(HAPE) and HACE was 0.73 % and 0.26 %,respectively,on the second to third day at altitude.Ataxia sign was measured by simple tests of coordination including a modified Romberg test.The clinical features of 62 patients with HACE were analyzed.It was found that the most frequent,serious neurological symptoms and signs were altered mental status(50/62,80.6 %)and truncal ataxia (47/62,75.8 %).Mental status change was rated slightly higher than ataxia,but ataxia occurred earlier than mental status change and other symptoms.The earliest sign of ataxia was a vague unsteadiness of gait,which may be present alone in association with or without AMS.Advanced ataxia was correlated with the AMS scores,but mild ataxia did not correlate with AMS scores at altitudes of 3750~4568 m.Of them,14 patients were further examined by computerized tomographic scanning of the brain and cerebral magnetic resonance imagines were examined in another 15 cases.These imaging studies indicated that the presence of the cerebral edema was in 97 % of cases who were clinically diagnosed as HACE (28/29).Ataxia seems to be a reliable sign of advanced AMS or HACE,so does altered mental status.

  12. Schistosomiasis transmission at high altitude crater lakes in Western Uganda

    Directory of Open Access Journals (Sweden)

    Philbert Clouds

    2008-08-01

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

  13. NHAP = National High-Altitude Aerial Photography: 1980 - 1989

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The National High Altitude Photography (NHAP) program, which was operated from 1980-1989, was coordinated by the U.S. Geological Survey as an interagency project to...

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

    CSIR Research Space (South Africa)

    Piketh, SJ

    1999-01-01

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

  15. NHAP = National High-Altitude Aerial Photography: 1980 - 1989

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The National High Altitude Photography (NHAP) program, which was operated from 1980-1989, was coordinated by the U.S. Geological Survey as an interagency project to...

  16. Travelling to new heights: practical high altitude medicine.

    Science.gov (United States)

    Plant, Tracie; Aref-Adib, Golnar

    2008-06-01

    Over 40 million people travel to high altitude for both work and pleasure each year, and all of them are at risk of the acute effects of hypoxia. This article reviews the prevention, diagnostic features and treatments of these illnesses.

  17. Functions and Design Scheme of Tibet High Altitude Test Base

    Institute of Scientific and Technical Information of China (English)

    Yu Yongqing; Guo Jian; Yin Yu; Mao Yan; Li Guangfan; Fan Jianbin; Lu Jiayu; Su Zhiyi; Li Peng; Li Qingfeng; Liao Weiming; Zhou Jun

    2010-01-01

    @@ The functional orientation of the Tibet High Altitude Test Base, subordinated to the State Grid Corporation of China (SGCC), is to serve power transmission projects in high altitude areas, especially to provide technical support for southwestern hydropower delivery projects by UHVDC transmission and Qinghai-Tibet grid interconnection project. This paper presents the matters concerned during siting and planning, functions,design scheme, the main performances and parameters of the test facilities, as well as the tests and research tasks already carried out.

  18. Functions and Design Scheme of Tibet High Altitude Test Base

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The functional orientation of the Tibet High Altitude Test Base, subordinated to the State Grid Corporation of China (SGCC), is to serve power transmission projects in high altitude areas, especially to provide technical support for southwestern hydropower delivery projects by UHVDC transmission and Qinghai-Tibet grid interconnection project. This paper presents the matters concerned during siting and planning, functions, design scheme, the main performances and parameters of the test facilities, as well as...

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

    Directory of Open Access Journals (Sweden)

    A. Mohammed

    2008-06-01

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

  20. High Altitude Weather Balloons to Support Rayleigh and Sodium Lidar Studies of the Troposphere, Stratosphere and Mesosphere at the Amundsen-Scott South Pole Station

    Science.gov (United States)

    Papen, George

    1995-01-01

    This proposal funded 100 high altitude weather balloons costing $15,500 to support the deployment of a Rayleigh/Raman/Na lidar at the South Pole. One year of measurements have been completed and it is estimated that the balloons will provide another 1-2 years of data.

  1. the APL Balloonborne High Altitude Research Platform (HARP)

    Science.gov (United States)

    Adams, D.; Arnold, S.; Bernasconi, P.

    2015-09-01

    The Johns Hopkins University Applied Physics Laboratory (APL) has developed and demonstrated a multi-purpose stratospheric balloonborne gondola known as the High Altitude Research Platform (HARP). HARP provides the power, mechanical supports, thermal control, and data transmission for multiple forms of high-altitude scientific research equipment. The platform has been used for astronomy, cosmology and heliophysics experiments but can also be applied to atmospheric studies, space weather and other forms of high altitude research. HARP has executed five missions. The first was Flare Genesis from Antarctica in 1993 and the most recent was the Balloon Observation Platform for Planetary Science (BOPPS) from New Mexico in 2014. HARP will next be used to perform again the Stratospheric Terahertz Observatory mission, a mission that it first performed in 2009. The structure, composed of an aluminum framework is designed for easy transport and field assembly while providing ready access to the payload and supporting avionics. A light-weighted structure, capable of supporting Ultra-Long Duration Balloon (ULDB) flights that can last more than 100 days is available. Scientific research payloads as heavy as 600 kg (1322 pounds) and requiring up to 800 Watts electrical power can be supported. The platform comprises all subsystems required to support and operate the science payload, including both line-of-sight (LOS) and over-the-horizon (0TH) telecommunications, the latter provided by Iridium Pilot. Electrical power is produced by solar panels for multi-day missions and batteries for single-day missions. The avionics design is primarily single-string; however, use of ruggedized industrial components provides high reliability. The avionics features a Command and Control (C&C) computer and a Pointing Control System (PCS) computer housed within a common unpressurized unit. The avionics operates from ground pressure to 2 Torr and over a temperature range from —30 C to +85 C

  2. Hydrological Modeling of the Upper Indus Basin: A Case Study from a High-Altitude Glacierized Catchment Hunza

    Directory of Open Access Journals (Sweden)

    Khan Garee

    2017-01-01

    Full Text Available The Soil andWater Assessment Tool (SWAT model combined with a temperature index and elevation band algorithm was applied to the Hunza watershed, where snow and glacier-melt are the major contributor to river flow. This study’s uniqueness is its use of a snow melt algorithm (temperature index with elevation bands combined with the SWAT, applied to evaluate the performance of the SWAT model in the highly snow and glacier covered watershed of the Upper Indus Basin in response to climate change on future streamflow volume at the outlet of the Hunza watershed, and its contribution to the Indus River System in both space and time, despite its limitation; it is not designed to cover the watershed of heterogeneous mountains. The model was calibrated for the years 1998–2004 and validated for the years 2008–2010. The model performance is evaluated using the four recommended statistical coefficients with uncertainty analysis (p-factor and r-factor. Simulations generated good calibration and validation results for the daily flow gauge. The model efficiency was evaluated, and a strong relationship was observed between the simulated and observed flows. The model results give a coefficient of determination (R2 of 0.82 and a Nash–Sutcliffe Efficiency index (NS of 0.80 for the daily flow with values of p-factor (79% and r-factor (76%. The SWAT model was also used to evaluate climate change impact on hydrological regimes, the target watershed with three GCMs (General Circulation Model of the IPCC fifth report for 2030–2059 and 2070–2099, using 1980–2010 as the control period. Overall, temperature (1.39 C to 6.58 C and precipitation (31% indicated increased variability at the end of the century with increasing river flow (5%–10%; in particular, the analysis showed smaller absolute changes in the hydrology of the study area towards the end of the century. The results revealed that the calibrated model was more sensitive towards temperature and

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

    Science.gov (United States)

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

    2015-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Martin Lara

    2012-01-01

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

  5. High-altitude wind resources in the Middle East

    KAUST Repository

    Yip, Chak Man Andrew

    2017-08-23

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

  6. High-altitude wind resources in the Middle East.

    Science.gov (United States)

    Yip, Chak Man Andrew; Gunturu, Udaya Bhaskar; Stenchikov, Georgiy L

    2017-08-29

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

  7. [Sperm count and seminal biochemistry of high altitude inhabitants and patients with chronic altitude sickness].

    Science.gov (United States)

    García-Hjarles, M A

    1989-04-01

    Semen analysis has been studied in 9 healthy adult males from sea level (150 m), age 19-32 years old and 15 healthy males from high altitude (NA), 9 from Cerro de Pasco (4,300 m) and 6 from Morococha (4,540 m), ages 19-45 years old. Five patients with chronic mountain sickness (MMC), whose ages ranged from 23 to 52 years old were also studied. The volume and motility were similar in NA and MMC, however both were below than in sea level subjects, but still in the normal range; the number of spermatozoa per 1 ml was lower at sea level than in NA and MMC, although the total number was higher at sea level due to the higher semen volume. Fructose at sea level was 356 +/- 53 mg/100 ml (mean +/- S.E.) which is similar to NA 237 +/- 45 whereas a MMC was significantly lower, 142 +/- 60. Citric acid was lower at sea level than in NA and MMC. Na, K and Cl, were similar among the three groups. The lower concentration of fructose in MMC parallels the decreased testicular function already found in these groups. However it is worthy to point out that the fertility is preserved in all the groups. The normal reproductive function in MMC is against the concept that this process occurs as a consequence of environmental disadaptation.

  8. The Experiment Study of the Influence on Plant Seeds and Aquatic Bio-logical Survival in High Altitude Environment

    Institute of Scientific and Technical Information of China (English)

    陈霈润

    2015-01-01

    There is A certain foundation in this experiment. It was the second time we did this experiment. The purposes are three parts, first, explore the 30000~40000 meters high sky with two cameras recording the scene. The Second, find out whether the high sky condition (temperature, air pressure, cosmic ray) make influence on plants seeds. The third, text whether normal aquatic animal is able to survive in high sky. The conclusions are also three parts. It is important to set a deadline for my group member to finish the assignment, and also check their process, or they might delay their own part of work or they are not in charge of the work. As the leader, I should be thoughtful. Not only about members’assignment, but also the details of their work, previously. Discuss about each task with group to ensure the correctness. Last but not least, every part of the experiment needs to be tested carefully. Only if we try our best to prevent accidents that might happen, then the experiment is able to suc⁃cess.

  9. Identification of novel serum peptide biomarkers for high-altitude adaptation: a comparative approach

    Science.gov (United States)

    Yang, Juan; Li, Wenhua; Liu, Siyuan; Yuan, Dongya; Guo, Yijiao; Jia, Cheng; Song, Tusheng; Huang, Chen

    2016-05-01

    We aimed to identify serum biomarkers for screening individuals who could adapt to high-altitude hypoxia at sea level. HHA (high-altitude hypoxia acclimated; n = 48) and HHI (high-altitude hypoxia illness; n = 48) groups were distinguished at high altitude, routine blood tests were performed for both groups at high altitude and at sea level. Serum biomarkers were identified by comparing serum peptidome profiling between HHI and HHA groups collected at sea level. Routine blood tests revealed the concentration of hemoglobin and red blood cells were significantly higher in HHI than in HHA at high altitude. Serum peptidome profiling showed that ten significantly differentially expressed peaks between HHA and HHI at sea level. Three potential serum peptide peaks (m/z values: 1061.91, 1088.33, 4057.63) were further sequence identified as regions of the inter-α trypsin inhibitor heavy chain H4 fragment (ITIH4 347-356), regions of the inter-α trypsin inhibitor heavy chain H1 fragment (ITIH1 205-214), and isoform 1 of fibrinogen α chain precursor (FGA 588-624). Expression of their full proteins was also tested by ELISA in HHA and HHI samples collected at sea level. Our study provided a novel approach for identifying potential biomarkers for screening people at sea level who can adapt to high altitudes.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-01

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

  11. Oxidative DNA damage and repair in skeletal muscle of humans exposed to high-altitude hypoxia

    DEFF Research Database (Denmark)

    Lundby, Carsten; Pilegaard, Henriette; van Hall, Gerrit

    2003-01-01

    ) was unaltered by prolonged hypoxia, in accordance with the notion that HO-1 is an acute stress response protein. In conclusion, our data indicate high-altitude hypoxia may serve as a good model for oxidative stress and that antioxidant genes are not upregulated in muscle tissue by prolonged hypoxia despite......Recent research suggests that high-altitude hypoxia may serve as a model for prolonged oxidative stress in healthy humans. In this study, we investigated the consequences of prolonged high-altitude hypoxia on the basal level of oxidative damage to nuclear DNA in muscle cells, a major oxygen...

  12. Metabolic and osmoregulatory function at low and high (3800 m) altitude.

    Science.gov (United States)

    Greene, H M; Cogger, E A; Miltenberger, T L; Koch, A K; Bray, R E; Wickler, S J

    2002-09-01

    Altitude evokes physiological adjustments that include not only respiratory and cardiovascular properties, but also metabolic function, renal and endocrine responses. The purpose of the present study was designed to expand our understanding of the physiological process involved with acclimatisation to high altitude in equids. The study examined temporal effects on metabolic and osmoregulatory function in horses (n = 6) at rest and postexercise at 3800 m. Animals were studied at 225 m (Pb = 743 mmHg) and during a 10 day stay at altitude (Pb = 487 mmHg). Rest samples were taken 90 min postprandial at 0830 h and immediately after the gallop phase of a standard exercise test. Changes in glucose, insulin, cortisol, thyroxine, sodium, potassium, chloride and total protein were assessed at both altitudes. Exercise stimulated increases in cortisol, thyroxine, potassium, and chloride; while the concentrations of glucose, insulin, sodium and total protein (regardless of altitude) decreased. Acute (Day 2) altitude exposure (following transport stress) produced significant increases in glucose, cortisol, thyroxine, chloride and protein at rest and exercise. All variables (except cortisol) appeared to stabilise by Day 4 of altitude exposure. Observations from these data (coupled with haematological and blood gases data) indicate that equids acutely acclimate within 2-3 days to this altitude.

  13. Microcomputer-controlled high-altitude data aquisition system

    Science.gov (United States)

    1985-05-01

    A new microcomputer controlled high altitude data acquisition system was developed. The system provides a new technique for data acquisition from China's astronomical, meteorological and other high altitude experiments and opens up new territory in microcomputer applications. This microcomputer controlled high altitude data acquisition system is made up of a Z80 single board computer, 10 K memory expansion board, and keyboard and display board which can collect 16 analog signals simultaneously, and through analog/digital conversion can convert external analog signals into digital signals then encode them in a certain form through program modulation and store them on audio cassette. The data is immediately retrieved from the tape and sent to the surface microcomputer system for data processing and analysis.

  14. Chironomidae (Diptera in the Himalayan Lakes – A study of sub-fossil assemblages in the sediments of two high altitude lakes from Nepal

    Directory of Open Access Journals (Sweden)

    Subodh Sharma

    2012-11-01

    Full Text Available Chironomid head capsules were identified from sediment cores taken from Lake Gokyo (4750 m and Lake Gosaikunda (4350 m in the east-central Himalaya, to determine taxonomic composition of chironomid assemblages over time.  The sedimentation rate of Lake Gosaikunda was estimated at 0.05 cm/yr and that of Gokyo was estimated at 0.07 cm/yr by 210Pb and 137Cs dating.  Micropsectra sp. was dominant in the sediments of both lakes.  Lake Gokyo sediments also contained Pseudodiamesa sp., Eukiefferiella/Tvetenia sp., Orthocladius/Cricotopus sp. and Rheocricotopus sp.  The concentration of headcapsules was nearly an order of magnitude greater in the Lake Gosaikunda core, which contained mostly Micropsectra sp. and Pseudodiamesa sp.  These taxa are typical of cold oligotrophic lakes.  Differences in lake depth, dissolved minerals, plus epi- and hypolimnetic temperature and dissolved oxygen suggest that stratification and temperature-induced increases in primary production may affect chironomid assemblages in these pristine lakes.  Palaeolimnological studies of Himalayan lakes should include replicate cores within lake, to increase headcapsule sample sizes given potentially high rates of sedimentation from glacial runoff. Key words: high altitude lakes, Himalaya, Chironomidae, palaeolimnology, Nepal

  15. A cross-sectional study of differences in 6-min walk distance in healthy adults residing at high altitude versus sea level

    Science.gov (United States)

    2014-01-01

    Background We sought to determine if adult residents living at high altitude have developed sufficient adaptation to a hypoxic environment to match the functional capacity of a similar population at sea level. To test this hypothesis, we compared the 6-min walk test distance (6MWD) in 334 residents living at sea level vs. at high altitude. Methods We enrolled 168 healthy adults aged ≥35 years residing at sea level in Lima and 166 individuals residing at 3,825 m above sea level in Puno, Peru. Participants completed a 6-min walk test, answered a sociodemographics and clinical questionnaire, underwent spirometry, and a blood test. Results Average age was 54.0 vs. 53.8 years, 48% vs. 43% were male, average height was 155 vs. 158 cm, average blood oxygen saturation was 98% vs. 90%, and average resting heart rate was 67 vs. 72 beats/min in Lima vs. Puno. In multivariable regression, participants in Puno walked 47.6 m less (95% CI -81.7 to -13.6 m; p < 0.01) than those in Lima. Other variables besides age and height that were associated with 6MWD include change in heart rate (4.0 m per beats/min increase above resting heart rate; p < 0.001) and percent body fat (-1.4 m per % increase; p = 0.02). Conclusions The 6-min walk test predicted a lowered functional capacity among Andean high altitude vs. sea level natives at their altitude of residence, which could be explained by an incomplete adaptation or a protective mechanism favoring neuro- and cardioprotection over psychomotor activity. PMID:24484777

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

    DEFF Research Database (Denmark)

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

    2001-01-01

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

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

    Science.gov (United States)

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

    2008-09-01

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

  18. High incidence of abnormal glucose metabolism in acute coronary syndrome patients at a moderate altitude: A sub-Himalayan study

    Directory of Open Access Journals (Sweden)

    Jitender Mokta

    2017-01-01

    Full Text Available Background: Abnormal glucose metabolic status at admission is an important marker of future cardiovascular events and long-term mortality after acute coronary syndrome (ACS, whether or not they are known diabetics. Objective: The aims were to study the prevalence of abnormal glucose metabolism in ACS patients and to compare the different methods of diagnosing diabetes in ACS patients. Methods: We did a prospective study. About 250 consecutive nondiabetic patients (200 men and 50 women with ACS admitted to a tertiary care institute of Himachal Pradesh in 1 year were enrolled. Admission plasma glucose, next morning fasting plasma glucose (FPG, A1C, and a standardized 75-g oral glucose tolerance test (OGTT 72 h after admission were done. Glucose metabolism was categorized as normal glucose metabolism, impaired glucose metabolism (impaired fasting glucose or impaired glucose tolerance [IGT], and diabetes. Diabetes was arbitrarily classified further as undiagnosed (HBA1c ≥6.5% or possibly stress diabetes (HBA1c <6.5%. A repeat OGTT after 3 months in objects with IGT and stress hyperglycemia at a time of admission was done. Results: The mean age was 54 ± 12.46 years. The mean plasma glucose at admission was 124 ± 53.96 mg/dL, and the mean FPG was 102 ± 27.07 mg/dL. The mean 2-h postglucose load concentration was 159.5 ± 56.58 mg/dL. At baseline, 95 (38% had normal glucose metabolism, 95 (38% had impaired glucose metabolism (IGT and or IGT and 60 (24% had diabetes; 48 (19.2% were undiagnosed diabetes and 12 (4.8% had stress hyperglycemia. At follow up 58.66% and 55.55% of patients with impaired glucose tolerance and stress hyperglycemia continued to have impaired glucose tolerance respectively. About 75 gm OGTT has highest sensitivity and specificity to diagnose diabetes, whereas A1C most specific to rule out stress hyperglycemia. Conclusions: In this small hilly state of India, abnormal glucose metabolism (previously undiagnosed diabetes and IGT

  19. High incidence of abnormal glucose metabolism in acute coronary syndrome patients at a moderate altitude: A sub-Himalayan study

    Science.gov (United States)

    Mokta, Jitender; Kumar, Subash; Ganju, Neeraj; Mokta, Kiran; Panda, Prashant Kumar; Gupta, Swatantra

    2017-01-01

    Background: Abnormal glucose metabolic status at admission is an important marker of future cardiovascular events and long-term mortality after acute coronary syndrome (ACS), whether or not they are known diabetics. Objective: The aims were to study the prevalence of abnormal glucose metabolism in ACS patients and to compare the different methods of diagnosing diabetes in ACS patients. Methods: We did a prospective study. About 250 consecutive nondiabetic patients (200 men and 50 women) with ACS admitted to a tertiary care institute of Himachal Pradesh in 1 year were enrolled. Admission plasma glucose, next morning fasting plasma glucose (FPG), A1C, and a standardized 75-g oral glucose tolerance test (OGTT) 72 h after admission were done. Glucose metabolism was categorized as normal glucose metabolism, impaired glucose metabolism (impaired fasting glucose or impaired glucose tolerance [IGT]), and diabetes. Diabetes was arbitrarily classified further as undiagnosed (HBA1c ≥6.5%) or possibly stress diabetes (HBA1c <6.5%). A repeat OGTT after 3 months in objects with IGT and stress hyperglycemia at a time of admission was done. Results: The mean age was 54 ± 12.46 years. The mean plasma glucose at admission was 124 ± 53.96 mg/dL, and the mean FPG was 102 ± 27.07 mg/dL. The mean 2-h postglucose load concentration was 159.5 ± 56.58 mg/dL. At baseline, 95 (38%) had normal glucose metabolism, 95 (38%) had impaired glucose metabolism (IGT and or IGT) and 60 (24%) had diabetes; 48 (19.2%) were undiagnosed diabetes and 12 (4.8%) had stress hyperglycemia. At follow up 58.66% and 55.55% of patients with impaired glucose tolerance and stress hyperglycemia continued to have impaired glucose tolerance respectively. About 75 gm OGTT has highest sensitivity and specificity to diagnose diabetes, whereas A1C most specific to rule out stress hyperglycemia. Conclusions: In this small hilly state of India, abnormal glucose metabolism (previously undiagnosed diabetes and IGT) is

  20. Transpulmonary plasma ET-1 and nitrite differences in high altitude pulmonary hypertension.

    Science.gov (United States)

    Berger, Marc M; Dehnert, Christoph; Bailey, Damian M; Luks, Andrew M; Menold, Elmar; Castell, Christian; Schendler, Guido; Faoro, Vitalie; Mairbäurl, Heimo; Bärtsch, Peter; Swenson, Erik R

    2009-01-01

    Berger, Marc M., Christoph Dehnert, Damian M. Bailey, Andrew M. Luks, Elmar Menold, Christian Castell, Guido Schendler, Vitalie Faoro, Heimo Mairbäurl, Peter Bärtsch, and Eric R. Swenson. Transpulmonary plasma ET-1 and nitrite differences in high altitude pulmonary hypertension. High Alt. Med. Biol. 10:17-24, 2009.- Thirty-four mountaineers were studied at low (110 m) and high altitude (4559 m) to evaluate if increased pulmonary artery systolic pressure (PASP) at high altitude is associated with increased pulmonary endothelin-1 (ET-1) availability and alterations in nitrite metabolism across the lung. Blood samples were obtained using central venous and radial artery catheters for plasma ET-1 and nitrite. Pulmonary blood flow was measured by inert gas rebreathing to calculate transpulmonary exchange of plasma ET-1 and nitrite, and PASP was assessed by transthoracic Doppler echocardiography. After ascent to high altitude, PASP increased from 23 +/- 4 to 39 +/- 10 mmHg. Arterial and central venous plasma ET-1 increased, while plasma nitrite did not change significantly. At low altitude there was a transpulmonary loss of plasma ET-1, but a transpulmonary gain at high altitude. In contrast was a transpulmonary gain of plasma nitrite at low altitude and a transpulmonary loss at high altitude. PASP positively correlated with a transpulmonary gain of plasma ET-1 and negatively correlated with a transpulmonary loss of plasma nitrite. These results suggest that a transpulmonary gain of plasma ET- 1 is associated with higher PASP at high altitude. Transpulmonary loss of plasma nitrite indicates either less pulmonary nitric oxide (NO) production, which contributes to higher PASP, or increased NO bioavailability arising from nitrite reduction, which may oppose ET-1-mediated vasoconstriction.

  1. Experimental study of the portable blood purification system for treatment of acute renal failure in dogs under the field condition in a high-altitude environment

    Directory of Open Access Journals (Sweden)

    Hai-bin LI

    2014-01-01

    Full Text Available Objective To reproduce the model of acute renal failure (ARF in beagles for comprehensively evaluating the safety, stability and validity of the continuous blood purification system under the field condition in a high-altitude environment. Methods Adult beagle ARF model was reproduced by bilateral nephrectomy. All ARF dogs underwent continuous veno-venous hemofiltration with a blood purification machine. Vital signs, renal function, liver function and plasma ion-levels before and after the therapy were analyzed through self-controlled study. Performance of the continuous blood purification machine running in a highaltitude environment was evaluated. Results Blood urea nitrogen (BUN and creatinine (Cr of six dogs were assayed 24 hours after nephrectomy, the difference showed statistical significance compared with those before the surgery (P<0.05, implying that six ARF models were reproduced successfully. Six dogs experienced continuous renal replacement therapy (CRRT with external jugular vein double-lumen tube placement (3 dogs or femoral vein catheter placement (3 dogs. Five dogs successfully finished the whole experiment, and one dog died because of falling off of the dialysis tube and blood loss. The continuous blood purification machine was sensitive with rapid release of warning signals when the condition was abnormal. Compared to that before CRRT, there were no statistically significant differences in heart rate, respiratory rate and blood pressure in ARF models 2, 4 hours after CRRT (P>0.05. And there were no statistically significant differences in ALT, AST and T-Bil in ARF models between that before and 2, 4 hours after CRRT (P>0.05. However, 2, 4 hours after CRRT, BUN and Cr levels descended significantly (P<0. 05, so was K+ level (P<0. 05. There were no complications such as hemorrhage or hypotension. There were no statistical differences in volume of replacement fluid or discarded fluid between before and after CRRT

  2. QT interval changes in term pregnant women living at moderately high altitude.

    Science.gov (United States)

    Batmaz, G; Aksoy, A N; Aydın, S; Ay, N K; Dane, B

    2016-01-01

    This study aimed to compare the QT interval changes in women with term pregnancy living at moderately high altitude (1890 m in Erzurum, Turkey) with those of women living at sea level (31 m in İstanbul, Turkey). One-hundred ten women (n = 55, for each group) with full-term and single child pregnancies. Two different locations in that state were selected: İstanbul, Turkey, which is at 31 m above sea level (Group 1) and Erzurum, Turkey, at 1890 m above sea level (Group 2). Physicians from the two locations participated in the study. We estimated QTc, QTc Max, QTc Min, QT, and QTcd intervals. Moderately high altitude group had significantly longer QT parameters (QTc, QTc Max, QTc Min, QT, and QTcd intervals) compared with sea level group (P anges occur in term pregnant women living moderately high altitude. These changes may be associated with pregnancy-related cardiovascular complications in moderately high altitude.

  3. Metabolic characteristics and response to high altitude in Phrynocephalus erythrurus (Lacertilia: Agamidae), a lizard dwell at altitudes higher than any other living lizards in the world.

    Science.gov (United States)

    Tang, Xiaolong; Xin, Ying; Wang, Huihui; Li, Weixin; Zhang, Yang; Liang, Shiwei; He, Jianzheng; Wang, Ningbo; Ma, Ming; Chen, Qiang

    2013-01-01

    Metabolic response to high altitude remains poorly explored in reptiles. In the present study, the metabolic characteristics of Phrynocephaluserythrurus (Lacertilia: Agamidae), which inhabits high altitudes (4500 m) and Phrynocephalusprzewalskii (Lacertilia: Agamidae), which inhabits low altitudes, were analysed to explore the metabolic regulatory strategies for lizards living at high-altitude environments. The results indicated that the mitochondrial respiratory rates of P. erythrurus were significantly lower than those of P. przewalskii, and that proton leak accounts for 74~79% of state 4 and 7~8% of state3 in P. erythrurus vs. 43~48% of state 4 and 24~26% of state3 in P. przewalskii. Lactate dehydrogenase (LDH) activity in P. erythrurus was lower than in P. przewalskii, indicating that at high altitude the former does not, relatively, have a greater reliance on anaerobic metabolism. A higher activity related to β-hydroxyacyl coenzyme A dehydrogenase (HOAD) and the HOAD/citrate synthase (CS) ratio suggested there was a possible higher utilization of fat in P. erythrurus. The lower expression of PGC-1α and PPAR-γ in P. erythrurus suggested their expression was not influenced by cold and low PO2 at high altitude. These distinct characteristics of P. erythrurus are considered to be necessary strategies in metabolic regulation for living at high altitude and may effectively compensate for the negative influence of cold and low PO2.

  4. Metabolic characteristics and response to high altitude in Phrynocephalus erythrurus (Lacertilia: Agamidae, a lizard dwell at altitudes higher than any other living lizards in the world.

    Directory of Open Access Journals (Sweden)

    Xiaolong Tang

    Full Text Available Metabolic response to high altitude remains poorly explored in reptiles. In the present study, the metabolic characteristics of Phrynocephaluserythrurus (Lacertilia: Agamidae, which inhabits high altitudes (4500 m and Phrynocephalusprzewalskii (Lacertilia: Agamidae, which inhabits low altitudes, were analysed to explore the metabolic regulatory strategies for lizards living at high-altitude environments. The results indicated that the mitochondrial respiratory rates of P. erythrurus were significantly lower than those of P. przewalskii, and that proton leak accounts for 74~79% of state 4 and 7~8% of state3 in P. erythrurus vs. 43~48% of state 4 and 24~26% of state3 in P. przewalskii. Lactate dehydrogenase (LDH activity in P. erythrurus was lower than in P. przewalskii, indicating that at high altitude the former does not, relatively, have a greater reliance on anaerobic metabolism. A higher activity related to β-hydroxyacyl coenzyme A dehydrogenase (HOAD and the HOAD/citrate synthase (CS ratio suggested there was a possible higher utilization of fat in P. erythrurus. The lower expression of PGC-1α and PPAR-γ in P. erythrurus suggested their expression was not influenced by cold and low PO2 at high altitude. These distinct characteristics of P. erythrurus are considered to be necessary strategies in metabolic regulation for living at high altitude and may effectively compensate for the negative influence of cold and low PO2.

  5. Mitochondrial function in human skeletal muscle following high-altitude exposure

    DEFF Research Database (Denmark)

    Jacobs, Robert A; Boushel, Robert; Wright-Paradis, Cynthia

    2013-01-01

    Studies regarding mitochondrial modifications in human skeletal muscle following acclimatization to high altitude are conflicting, and these inconsistencies may be due to the prevalence of representing mitochondrial function through static and isolated measurements of specific mitochondrial.......059) to limit mass-specific maximal oxidative phosphorylation capacity. These data suggest that 9-11 days of exposure to high altitude do not markedly modify integrated measures of mitochondrial functional capacity in skeletal muscle despite significant decrements in the concentrations of enzymes involved...

  6. Analysis of mitochondrial DNA in Tibetan gastric cancer patients at high altitude

    OpenAIRE

    Jiang, Jun; Zhao, Jun-Hui; Wang, Xue-Lian; DI, JI; Liu, Zhi-Bo; Li, Guo-Yuan; WANG, MIAO-ZHOU; Li, Yan; Chen, Rong; Ge, Ri-Li

    2015-01-01

    The highest risk areas of gastric cancer are currently Japan, Korea and China; Qinghai, a high-altitude area, has one of the highest gastric cancer rates in China. The incidence of gastric cancer is higher in the Tibetan ethnic group compared to that in the Han ethnic group in Qinghai. This study was conducted to determine the clinical characteristics of mitochondrial DNA (mtDNA) mutations and copy numbers among Tibetans with gastric cancer residing at high altitudes and investigate the assoc...

  7. Climate Change Impacts on High-Altitude Ecosystems

    Directory of Open Access Journals (Sweden)

    Harald Pauli

    2016-02-01

    Full Text Available Reviewed: Climate Change Impacts on High-Altitude Ecosystems By Münir Öztürk, Khalid Rehman Hakeem, I. Faridah-Hanum and Efe. Recep, Cham, Switzerland: Springer International Publishing, 2015. xvii + 696 pp. US$ 239.00. ISBN 978-3-319-12858-0.

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

    DEFF Research Database (Denmark)

    Sutton, J R; Lassen, N

    1979-01-01

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

  9. Chicxulub High-Altitude Ballistic Ejecta from Central Belize

    Science.gov (United States)

    Pope, K. O.; Ocampo, A. C.

    2000-01-01

    Chicxulub ejecta are found in central Belize, 475 km southeast of the impact crater center. These deposits are ballistic ejecta launched along high-altitude trajectories above the atmosphere and deposited as a discontinuous sheet on the terminal Cretaceous land surface.

  10. Flight Control of the High Altitude Wind Power System

    NARCIS (Netherlands)

    Podgaets, A.R.; Ockels, W.J.

    2007-01-01

    Closed loop Laddermill flight control problem is considered in this paper. Laddermill is a high altitude kites system for energy production. The kites have been simulated as rigid bodies and the cable as a thin elastic line. Euler angles and cable speed are controls. Flight control is written as a f

  11. Abnormal blood flow in the sublingual microcirculation at high altitude

    NARCIS (Netherlands)

    Martin, D.S.; Ince, C.; Goedhart, P.; Levett, D.Z.H.; Grocott, M.P.W.

    2009-01-01

    We report the first direct observations of deranged microcirculatory blood flow at high altitude, using sidestream dark-field imaging. Images of the sublingual microcirculation were obtained from a group of 12 volunteers during a climbing expedition to Cho Oyu (8,201 m) in the Himalayas.

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

    African Journals Online (AJOL)

    in our region. Keywords: Acute mesenteric ischemia, high altitude, Saudi Arabia. Résumé .... Saudi Arabia for many diseases such as stroke,[13] deep venous .... intestinal vascular failure: a collective review of 43 cases in Taiwan. Br J Clin ...

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

    DEFF Research Database (Denmark)

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

    2003-01-01

    conditions. However, this fails to take into account that oxygen solubility declines with decreasing atmospheric pressure, which may be of importance at high altitudes. 2. Based on samples of macroinvertebrate benthos and in situ measurements of respiratory oxygen demand of macroinvertebrates in small...

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

    Science.gov (United States)

    Brutsaert, Tom

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

  15. Effect of high altitude exposure on spermatogenesis and epididymal sperm count in male rats.

    Science.gov (United States)

    Gasco, M; Rubio, J; Chung, A; Villegas, L; Gonzales, G F

    2003-12-01

    The present study was designed to determine the effect of exposure to high altitude on spermatogenesis using transillumination technique and sperm count in male rats. In addition, the effect of oral intubation for intragastric administration of vehicle on testicular parameters in adult male rats in a schedule of 42 days was assessed. Male rats were exposed to Cerro de Pasco (Peru) at 4340 m for 3, 7, 14, 21, 28, 35 and 42 days resulting in a modification of the pattern of the seminiferous tubule stages. At day 3, stages I, IV-V, VI, VII and IX-XI were relatively shorter at high altitude than at sea level. At day 7, stages VIII, IX-XI, XII and XIII-XIV were reduced. At day 14, stages VII, VIII and IX-XI were reduced. At day 21 and 28, stages VIII, XII and XIII-XIV were significantly increased at high altitude. At day 35 an increase in stage XIII-XIV was observed. At day 42, stages II-III, IX-XI and XII were significantly increased at high altitude. Epididymal sperm count was significantly reduced at day 7 of exposure to high altitude and maintained low levels with respect to sea level up to 42 days. In conclusion, high altitude exposure affects spermatogenesis, particularly onset of mitosis and spermiation. This in turn affects epididymal sperm count.

  16. HCN ice in Titan's high-altitude southern polar cloud

    CERN Document Server

    de Kok, Remco J; Maltagliati, Luca; Irwin, Patrick G J; Vinatier, Sandrine

    2014-01-01

    Titan's middle atmosphere is currently experiencing a rapid change of season after northern spring arrived in 2009. A large cloud was observed for the first time above Titan's southern pole in May 2012, at an altitude of 300 km. This altitude previously showed a temperature maximum and condensation was not expected for any of Titan's atmospheric gases. Here we show that this cloud is composed of micron-sized hydrogen cyanide (HCN) ice particles. The presence of HCN particles at this altitude, together with new temperature determinations from mid-infrared observations, indicate a very dramatic cooling of Titan's atmosphere inside the winter polar vortex in early 2012. Such a cooling is completely contrary to previously measured high-altitude warming in the polar vortex, and temperatures are a hundred degrees colder than predicted by circulation models. Besides elucidating the nature of Titan's mysterious polar cloud, these results thus show that post-equinox cooling at the winter pole is much more efficient th...

  17. High serum zinc and serum testosterone levels were associated with excessive erythrocytosis in men at high altitudes.

    Science.gov (United States)

    Gonzales, Gustavo F; Tapia, Vilma; Gasco, Manuel; Rubio, Julio; Gonzales-Castañeda, Cynthia

    2011-12-01

    Chronic mountain sickness (CMS), a lack of adaptation to altitude characterized by excessive erythrocytosis (EE), is a health problem associated with life at high altitude. The erythropoietic process is regulated by both erythropoietin and testosterone. Zinc (Zn) is known to be related with testosterone and hemoglobin levels; meanwhile, nitric oxide was also associated with adaptation to high altitude. The aim of this study was to determine the relationship of hemoglobin and CMS score with serum levels of zinc, total testosterone (TT), calculated free testosterone (cFT), bioavailable testosterone (BAT), hemoglobin, and nitric oxide in men at high altitude with or without EE. Men residing in Lima (150 m) and Cerro de Pasco (4,340 m), Peru, were divided into three groups: (1) low altitude, (2) high altitude without EE (hemoglobin < 21 g/dl), and (3) high altitude with EE (hemoglobin ≥ 21 g/dl). Adjusted multivariable regression models showed that serum testosterone (total or free) and Zn levels were independently correlated with increased hemoglobin levels. Similarly, hemoglobin was positively related with signs/symptoms of CMS; however, both increased the serum Zn and the nitric oxide levels correlated with reduced risk for signs/symptoms of CMS. In conclusion, higher serum testosterone levels and Zn levels were associated with EE, and low scores of signs/symptoms of CMS were associated with higher Zn and nitric oxide levels.

  18. Latest news from the High Altitude Water Cherenkov Observatory

    Science.gov (United States)

    González Muñoz, A.; HAWC Collaboration

    2016-07-01

    The High Altitude Water Cherenkov Observatory is an air shower detector designed to study very-high-energy gamma rays (˜ 100 GeV to ˜ 100 TeV). It is located in the Pico de Orizaba National Park, Mexico, at an elevation of 4100 m. HAWC started operations since August 2013 with 111 tanks and in April of 2015 the 300 tanks array was completed. HAWC's unique capabilities, with a field of view of ˜ 2 sr and a high duty cycle of 5%, allow it to survey 2/3 of the sky every day. These features makes HAWC an excellent instrument for searching new TeV sources and for the detection of transient events, like gamma-ray bursts. Moreover, HAWC provides almost continuous monitoring of already known sources with variable gamma-ray fluxes in most of the northern and part of the southern sky. These observations will bring new information about the acceleration processes that take place in astrophysical environments. In this contribution, some of the latest scientific results of the observatory will be presented.

  19. Highlights from the High Altitude Water Cherenkov Observatory

    CERN Document Server

    Pretz, John

    2015-01-01

    The High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory was completed this year at a 4100-meter site on the flank of the Sierra Negra volcano in Mexico. HAWC is a water Cherenkov ground array with the capability to distinguish 100 GeV - 100 TeV gamma rays from the hadronic cosmic-ray background. HAWC is uniquely suited to study extremely high energy cosmic-ray sources, search for regions of extended gamma-ray emission, and to identify transient gamma-ray phenomena. HAWC will play a key role in triggering multi-wavelength and multi-messenger studies of active galaxies, gamma-ray bursts, supernova remnants and pulsar wind nebulae. Observation of TeV photons also provide unique tests for a number of fundamental physics phenomena including dark matter annihilation and primordial black hole evaporation. Operation began mid-2013 with the partially-completed detector. Multi-TeV emission from the Galactic Plane is clearly seen in the first year of operation, confirming a number of known TeV sources, and a numb...

  20. Cerebral autoregulation in subjects adapted and not adapted to high altitude.

    Science.gov (United States)

    Jansen, G F; Krins, A; Basnyat, B; Bosch, A; Odoom, J A

    2000-10-01

    Impaired cerebral autoregulation (CA) from high-altitude hypoxia may cause high-altitude cerebral edema in newcomers to a higher altitude. Furthermore, it is assumed that high-altitude natives have preserved CA. However, cerebral autoregulation has not been studied at altitude. We studied CA in 10 subjects at sea level and in 9 Sherpas and 10 newcomers at an altitude of 4243 m by evaluating the effect of an increase of mean arterial blood pressure (MABP) with phenylephrine infusion on the blood flow velocity in the middle cerebral artery (Vmca), using transcranial Doppler. Theoretically, no change of Vmca in response to an increase in MABP would imply perfect autoregulation. Complete loss of autoregulation is present if Vmca changes proportionally with changes of MABP. In the sea-level group, at a relative MABP increase of 23+/-4% during phenylephrine infusion, relative Vmca did not change essentially from baseline Vmca (2+/-7%, P=0.36), which indicated intact autoregulation. In the Sherpa group, at a relative MABP increase of 29+/-7%, there was a uniform and significant increase of Vmca of 24+/-9% (P<0.0001) from baseline Vmca, which indicated loss of autoregulation. The newcomers showed large variations of Vmca in response to a relative MABP increase of 21+/-6%. Five subjects showed increases of Vmca of 22% to 35%, and 2 subjects showed decreases of Vmca of 21% and 23%. All Sherpas and the majority of the newcomers showed impaired CA. It indicates that an intact autoregulatory response to changes in blood pressure is probably not a hallmark of the normal human cerebral vasculature at altitude and that impaired CA does not play a major role in the occurrence of cerebral edema in newcomers to the altitude.

  1. Nike Black Brant V high altitude dynamic instability characteristics

    Science.gov (United States)

    Montag, W. H.; Walker, L. L., Jr.

    1979-01-01

    Flight experience on the Nike Black Brant V has demonstrated the existence of plume induced flow separation over the fins and aft body of the Black Brant V motor. Modelling of the forces associated with this phenomenon as well as analysis of the resultant vehicle coning motion and its effect on the velocity vector heading are presented. A summary of Nike Black Brant V flight experience with high altitude dynamic instability is included.

  2. Nike Black Brant V high altitude dynamic instability characteristics

    Science.gov (United States)

    Montag, W. H.; Walker, L. L., Jr.

    1979-01-01

    Flight experience on the Nike Black Brant V has demonstrated the existence of plume induced flow separation over the fins and aft body of the Black Brant V motor. Modelling of the forces associated with this phenomenon as well as analysis of the resultant vehicle coning motion and its effect on the velocity vector heading are presented. A summary of Nike Black Brant V flight experience with high altitude dynamic instability is included.

  3. [High frequency of dyslipidemia and impaired fasting glycemia in a high altitude Peruvian population].

    Science.gov (United States)

    Málaga, Germán; Zevallos-Palacios, Claudia; Lazo, María de los Ángeles; Huayanay, Carlos

    2010-01-01

    We performed a cross sectional study in Lari (3600 m), a highland rural community from Arequipa, Peru. We evaluated a body mass index (BMI), glycemia and lipid profile in 74 over 18 year persons. The mean age was 51.7 ± 18.0 years, 62.2% were women, mean of BMI was 25.6 ± 3.7. Prevalence of hypercholesterolemia was 40.6%, "low HDL" in 77% of the population (93.5% in women vs 50% in men, p <0.001) and elevated level of LDL was 71.7%. The prevalence of impaired fasting glycemia was 27%. In conclusion, we found high prevalence of impaired fasting glycemia, hypercholesterolemia and especially "low HDL" in high altitude rural natives. These findings must be considered to realize interventions in high altitude populations to avoid future cardiovascular complications.

  4. High Altitude Long Endurance UAV Analysis Model Development and Application Study Comparing Solar Powered Airplane and Airship Station-Keeping Capabilities

    Science.gov (United States)

    Ozoroski, Thomas A.; Nickol, Craig L.; Guynn, Mark D.

    2015-01-01

    There have been ongoing efforts in the Aeronautics Systems Analysis Branch at NASA Langley Research Center to develop a suite of integrated physics-based computational utilities suitable for modeling and analyzing extended-duration missions carried out using solar powered aircraft. From these efforts, SolFlyte has emerged as a state-of-the-art vehicle analysis and mission simulation tool capable of modeling both heavier-than-air (HTA) and lighter-than-air (LTA) vehicle concepts. This study compares solar powered airplane and airship station-keeping capability during a variety of high altitude missions, using SolFlyte as the primary analysis component. Three Unmanned Aerial Vehicle (UAV) concepts were designed for this study: an airplane (Operating Empty Weight (OEW) = 3285 kilograms, span = 127 meters, array area = 450 square meters), a small airship (OEW = 3790 kilograms, length = 115 meters, array area = 570 square meters), and a large airship (OEW = 6250 kilograms, length = 135 meters, array area = 1080 square meters). All the vehicles were sized for payload weight and power requirements of 454 kilograms and 5 kilowatts, respectively. Seven mission sites distributed throughout the United States were selected to provide a basis for assessing the vehicle energy budgets and site-persistent operational availability. Seasonal, 30-day duration missions were simulated at each of the sites during March, June, September, and December; one-year duration missions were simulated at three of the sites. Atmospheric conditions during the simulated missions were correlated to National Climatic Data Center (NCDC) historical data measurements at each mission site, at four flight levels. Unique features of the SolFlyte model are described, including methods for calculating recoverable and energy-optimal flight trajectories and the effects of shadows on solar energy collection. Results of this study indicate that: 1) the airplane concept attained longer periods of on

  5. Does high altitude increase risks of the elderly patients with coronary artery disease?

    Institute of Scientific and Technical Information of China (English)

    Tian-Yi Wu; Zhong-Yan Zhan; Qin-Li Wu; Suo-Lung Baomu; Yu-Ling Jie; Min Sun

    2009-01-01

    Objective To assess the effect of altitude hypoxia on the elderly patients with coronary artery disease (CAD). Methods Three subject groups were surveyed during their train trip on the highest railroad--the Qinghai-Tibet Railway: 22 elderly individuals with documented CAD, 20 healthy elderly controls, and 20 healthy young controls, all of whom from Beijing near the sea level (76 m). Survey questions addressed clinical features of their healthy conditions and aspects of their coronary disease. The baseline study was performed at Xining at an altitude of 2261 m, and then during acute exposure to altitudes of 2808 m, 4768m, 5072 m and 4257 m by train for 24 hours. Resting pulse rate, blood pressure, oxygen saturation, electrocardiograph (ECG), and cardiac work estimated by the heart rate-blood pressure double product were obtained five times in each subject at different altitudes. Results On arrival to altitudes between 4768 m and 5072 m, the older passengers, especially those with preexisting coronary disease, had higher HR, higher BP, and lower SaO2, as well as more frequent abnormalities on ECG, as compared to the younger healthy subjects. As compared with the healthy elderly controls, incomplete right bundle branch block, left ventricular hypertrophy, and ST segment depression were more frequently seen in the elderly coronary patients (P<0.01). Cardiac work in group 1 was increased by 13% 12 hours after arrival to altitudes between 2808 m and 5072 m. Oxygen saturation decreased significantly with the altitude increasing by train ascent but improved after inhalation of oxygen. Most of the older subjects tolerated their sojourn at high altitude well except one who developed angina repeatedly with a significant ST segment depression. Conclusions Coronary events and ECG signs of myocardial ischemia are rare in elderly individuals with CAD who travel from sea level to moderate altitudes of 1500m to 2800 m. Patients with CAD who are well compensated at sea level

  6. High Altitude Venus Operational Concept (HAVOC): Proofs of Concept

    Science.gov (United States)

    Jones, Christopher A.; Arney, Dale C.; Bassett, George Z.; Clark, James R.; Hennig, Anthony I.; Snyder, Jessica C.

    2015-01-01

    The atmosphere of Venus is an exciting destination for both further scientific study and future human exploration. A recent internal NASA study of a High Altitude Venus Operational Concept (HAVOC) led to the development of an evolutionary program for the exploration of Venus, with focus on the mission architecture and vehicle concept for a 30-day crewed mission into Venus's atmosphere at 50 kilometers. Key technical challenges for the mission include performing the aerocapture maneuvers at Venus and Earth, inserting and inflating the airship at Venus during the entry sequence, and protecting the solar panels and structure from the sulfuric acid in the atmosphere. Two proofs of concept were identified that would aid in addressing some of the key technical challenges. To mitigate the threat posed by the sulfuric acid ambient in the atmosphere of Venus, a material was needed that could protect the systems while being lightweight and not inhibiting the performance of the solar panels. The first proof of concept identified candidate materials and evaluated them, finding FEP-Teflon (Fluorinated Ethylene Propylene-Teflon) to maintain 90 percent transmittance to relevant spectra even after 30 days of immersion in concentrated sulfuric acid. The second proof of concept developed and verified a packaging algorithm for the airship envelope to inform the entry, descent, and inflation analysis.

  7. Chronic intermittent high altitude exposure, occupation, and body mass index in workers of mining industry.

    Science.gov (United States)

    Esenamanova, Marina K; Kochkorova, Firuza A; Tsivinskaya, Tatyana A; Vinnikov, Denis; Aikimbaev, Kairgeldy

    2014-09-01

    The obesity and overweight rates in population exposed to chronic intermittent exposure to high altitudes are not well studied. The aim of the retrospective study was to evaluate whether there are differences in body mass index in different occupation groups working in intermittent shifts at mining industry at high altitude: 3800-4500 meters above sea level. Our study demonstrated that obesity and overweight are common in workers of high altitude mining industry exposed to chronic intermittent hypoxia. The obesity rate was lowest among miners as compared to blue- and white-collar employees (9.5% vs. 15.6% and 14.7%, p=0.013). Obesity and overweight were associated with older age, higher rates of increased blood pressure (8.79% and 5.72% vs. 1.92%), cholesterol (45.8% and 45.6% vs. 32.8%) and glucose (4.3% and 1.26% vs. 0.57%) levels as compared to normal body mass index category (pmining industry exposed to intermittent high-altitude hypoxia. Therefore, assessment and monitoring of body mass index seems to be essential in those who live and work at high altitudes to supply the correct nutrition, modify risk factors, and prevent related disorders.

  8. Reconciling high-altitude precipitation in the upper Indus basin with glacier mass balances and runoff

    Science.gov (United States)

    Immerzeel, Walter; Wanders, Niko; Lutz, Arthur; Shea, Joseph; Bierkens, Marc

    2016-04-01

    Mountain ranges in Asia are important water suppliers, especially if downstream climates are arid, water demands are high and glaciers are abundant. In such basins, the hydrological cycle depends heavily on high-altitude precipitation. Yet direct observations of high-altitude precipitation are lacking and satellite derived products are of insufficient resolution and quality to capture spatial variation and magnitude of mountain precipitation. Here we use glacier mass balances to inversely infer the high-altitude precipitation in the upper Indus basin and show that the amount of precipitation required to sustain the observed mass balances of large glacier systems is far beyond what is observed at valley stations or estimated by gridded precipitation products. An independent validation with observed river flow confirms that the water balance can indeed only be closed when the high altitude precipitation on average is more than twice as high and in extreme cases up to a factor of 10 higher than previously thought. We conclude that these findings alter the present understanding of high-altitude hydrology and will have an important bearing on climate change impact studies, planning and design of hydropower plants and irrigation reservoirs as well as the regional geopolitical situation in general.

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

    Directory of Open Access Journals (Sweden)

    Pandey P

    2015-11-01

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

  10. Edema pulmonar de gran altura HIGH ALTITUDE PULMONARY EDEMA

    Directory of Open Access Journals (Sweden)

    FELIPE UNDURRAGA M

    2003-04-01

    Full Text Available Las enfermedades de altura son de causa cerebral y pulmonar. Las primeras se refieren fundamentalmente al mal agudo de montaña y al edema cerebral de altura y las segundas al edema pulmonar agudo de montaña. Actuales evidencias señalan que el edema cerebral sería un fenómeno universal de los que ascienden a altura y que tres de cada cuatro individuos sanos que se expongan a altura desarrollarán un edema pulmonar agudo de montaña subclínico. La hipoxia de altura es la responsable de estos cuadros y los sujetos susceptibles serían aquellos que genéticamente tienen una respuesta ventilatoria reducida a la hipoxia y una exagerada respuesta vasopresora pulmonar al ejercicio.Se presenta un caso de edema pulmonar agudo de montaña en un deportista previamente sano que participó en una expedición al cerro El Plomo (5.280 msnm en la Cordillera de los Andes central. Posteriormente, se comenta la fisiopatología y tratamiento de esta condiciónHigh altitude diseases are originated from brain and lung. The first are Acute Mountain Sickness and Brain edema and the second is High Altitude Pulmonary Edema (HAPE. Current evidence shows that brain edema is an universal event of the people who are exposed to high altitude. By other hand 3 out of 4 healthy subjects exposed to high altitude will present a subclinical HAPE. Hypoxia of altitude is the responsable for this condition. The susceptible subjects would be those who genetically have a low ventilatory response to hypoxia and an exaggerated increase of vascular pulmonary pressure during exercise. A clinical case of acute pulmonary edema in a young sportman who participated in an expedition to Cerro El Plomo (5.280 m in Chilean Central Andes Mountains is presented. Pathophysiology and treatment of these conditions are discussed

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

    Data.gov (United States)

    National Aeronautics and Space Administration — High-altitude balloon flights are an inexpensive method used to lift payloads to high altitudes. Federal Aviation Administration (FAA) regulations permit payloads...

  12. High altitude hypoxia and blood pressure dysregulation in adult chickens.

    Science.gov (United States)

    Herrera, E A; Salinas, C E; Blanco, C E; Villena, M; Giussani, D A

    2013-02-01

    Although it is accepted that impaired placental perfusion in complicated pregnancy can slow fetal growth and programme an increased risk of cardiovascular dysfunction at adulthood, the relative contribution of reductions in fetal nutrition and in fetal oxygenation as the triggering stimulus remains unclear. By combining high altitude (HA) with the chick embryo model, we have previously isolated the direct effects of HA hypoxia on embryonic growth and cardiovascular development before hatching. This study isolated the effects of developmental hypoxia on cardiovascular function measured in vivo in conscious adult male and female chickens. Chick embryos were incubated, hatched and raised at sea level (SL, nine males and nine females) or incubated, hatched and raised at HA (seven males and seven females). At 6 months of age, vascular catheters were inserted under general anaesthesia. Five days later, basal blood gas status, basal cardiovascular function and cardiac baroreflex responses were investigated. HA chickens had significantly lower basal arterial PO2 and haemoglobin saturation, and significantly higher haematocrit than SL chickens, independent of the sex of the animal. HA chickens had significantly lower arterial blood pressure than SL chickens, independent of the sex of the animal. Although the gain of the arterial baroreflex was decreased in HA relative to SL male chickens, it was increased in HA relative to SL female chickens. We show that development at HA lowers basal arterial blood pressure and alters baroreflex sensitivity in a sex-dependent manner at adulthood.

  13. Naturally enhanced ion-acoustic lines at high altitudes

    Directory of Open Access Journals (Sweden)

    Y. Ogawa

    2006-12-01

    Full Text Available Naturally enhanced ion-acoustic lines (NEIALs between 1200 and 1900 km altitude are investigated. The NEIALs were found in the background gates of data from the European Incoherent Scatter (EISCAT Svalbard radar (ESR at 78° N looking field-aligned. Only strongly enhanced lines are detected at such high altitudes. The estimated enhancement above incoherent scattering integrated over the antenna beam and preintegration time of 10 s reaches about 10 000. Both lines are always enhanced above 1000 km altitude, and the downshifted line, corresponding to upward propagating ion-acoustic waves, is always stronger than the upshifted line, for downgoing waves. The ratio of the downshifted and upshifted peaks is often remarkably constant along a profile. Using the line positions as indicators of the ion-acoustic speeds and the bulk drift velocity, we find that the bulk drift does not exceed the ion-acoustic (sound speed, but extrapolation of the profiles suggests that the sound barrier is reached around 2000 km in one event. The highest ion-acoustic speed is seen near 600 km, above the density peak, indicating that electrons are heated not only by ionizing precipitation but significantly also by upgoing waves. Upflow continues to speed up above the estimated temperature maximum. A certain qualitative similarity to the solar corona seems to be the case.

  14. Birth weight and altitude: a study in Peruvian communities.

    Science.gov (United States)

    Mortola, J P; Frappell, P B; Aguero, L; Armstrong, K

    2000-03-01

    We tested the hypothesis that at high altitude birth weight decreases once a critical barometric pressure (Pb) is reached. Birth weight data covering the 1-year period from November 1997 to October 1998 were collected in Peru from the data files of 15 community and mining centers between sea level and 4575 m altitude. These centers are scattered along the main road that joins Lima (on the Pacific shore) to Cerro de Pasco (4330 m) and surroundings. Above approximately 2000 m (ie, at Pb below approximately 590 mm Hg, inspired O(2) partial pressure of approximately 114 mm Hg) and up to approximately 4500 m altitude birth weight declined at an average of 65 g for every additional 500 m altitude (or 105 g for every additional 50 mm Hg drop in Pb). This pattern did not differ between sexes. Averages and modal distributions of the birth weight from 2 hospitals in Cerro de Pasco (4330 m) serving different social groups were similar. Body length at birth was similar at various altitudes, with the exception of the 2 highest locations above 4500 m, where it was slightly reduced. From these data, together with additional data collected in the North of Peru (Chacas, 3360 m) and with results from other ethnic groups previously published, we conclude that the drop in birth weight at altitude is (1) apparent once the critical Pb of approximately 590 mm Hg is reached, corresponding to an altitude of approximately 2000 m, (2) proportional to the increase in altitude between approximately 2000 m and 4500 m, and (3) independent from socioeconomic factors.

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

    Science.gov (United States)

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

    2017-01-01

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

  16. Analysis of high altitude clouds in the martian atmosphere based on Mars Climate Sounder observations

    Science.gov (United States)

    Puspitarini, L.; Määttänen, A.; Fouchet, T.; Kleinboehl, A.; Kass, D. M.; Schofield, J. T.

    2016-11-01

    High altitude clouds have been observed in the Martian atmosphere. However, their properties still remain to be characterized. Mars Climate Sounder (MCS) aboard Mars Reconnaissance Orbiter (MRO) is an instrument that measures radiances in the thermal infrared, both in limb and nadir views. It allows us to retrieve vertical profiles of radiance, temperature and aerosols. Using the MCS data and radiative transfer model coupled with an automated inversion routine, we can investigate the chemical composition of the high altitude clouds. We will present the first results on the properties of the clouds. CO2 ice is the best candidate to be the main component of some high altitude clouds due to the most similar spectral variation compared to water ice or dust, in agreement with previous studies. Using cloud composition of contaminated CO2 ice (dust core surrounded by CO2 ice) might improve the fitting result, but further study is needed.

  17. Compositae Plants Differed in Leaf Cuticular Waxes between High and Low Altitudes.

    Science.gov (United States)

    Guo, Na; Gao, Jianhua; He, Yuji; Guo, Yanjun

    2016-06-01

    We sampled eight Compositae species at high altitude (3482 m) and seven species at low altitude (220 m), analyzed the chemical compositions and contents of leaf cuticular wax, and calculated the values of average chain length (ACL), carbon preference index (CPI), dispersion (d), dispersion/weighted mean chain length (d/N), and C31 /(C31  + C29 ) (Norm31). The amounts of total wax and compositions were significantly higher at high altitude than at low altitude, except for primary alcohol, secondary alcohol, and ketone. The main n-alkanes in most samples were C31 , C29 , and C33 . Low altitude had more C31 and C33 , whereas more C29 occurred at high altitude. The ACL, CPI, d, d/N, and Norma 31 were higher at low altitude than at high altitude. The fatty acid and primary alcohol at low altitude contained more C26 homologous than at high altitude. More short-chain primary alcohols were observed at high altitude. At low altitude, the primary alcohol gave on average the largest amount, while it was n-alkane at high altitude. These results indicated that the variations of leaf cuticular waxes benefited Compositae plants to adapt to various environmental stresses and enlarge their distribution.

  18. Mitogenomic analyses propose positive selection in mitochondrial genes for high-altitude adaptation in galliform birds.

    Science.gov (United States)

    Zhou, Taicheng; Shen, Xuejuan; Irwin, David M; Shen, Yongyi; Zhang, Yaping

    2014-09-01

    Galliform birds inhabit very diverse habitats, including plateaus that are above 3000 m in altitude. At high altitude, lower temperature and hypoxia are two important factors influencing survival. Mitochondria, as the ultimate oxygen transductor, play an important role in aerobic respiration through oxidative phosphorylation (OXPHOS). We analyzed the mitochondrial genomes of six high-altitude phasianidae birds and sixteen low-altitude relatives in an attempt to determine the role of mitochondrial genes in high-altitude adaptation. We reconstructed the phylogenetic relationships of these phasianidae birds and relatives and found at least four lineages that independently occupied this high-altitude habitat. Selective analyses revealed significant evidence for positive selection in the genes ND2, ND4, and ATP6 in three of the high-altitude lineages. This result strongly suggests that adaptive evolution of mitochondrial genes played a critical role during the independent acclimatization to high altitude by galliform birds.

  19. Increased insulin requirements during exercise at very high altitude in type 1 diabetes

    NARCIS (Netherlands)

    de Mol, Pieter; de Vries, Suzanna T.; de Koning, Eelco J. P.; Gans, Rijk O. B.; Tack, Cees J.; Bilo, Henk J. G.

    2011-01-01

    OBJECTIVE-Safe, very high altitude trekking in subjects with type 1 diabetes requires understanding of glucose regulation at high altitude. We investigated insulin requirements, energy expenditure, and glucose levels at very high altitude in relation to acute mountain sickness (AMS) symptoms in indi

  20. Increased insulin requirements during exercise at very high altitude in type 1 diabetes

    NARCIS (Netherlands)

    Mol, P. De; Vries, S.T. de; Koning, E.J. de; Gans, R.O.; Tack, C.J.J.; Bilo, H.J.

    2011-01-01

    OBJECTIVE: Safe, very high altitude trekking in subjects with type 1 diabetes requires understanding of glucose regulation at high altitude. We investigated insulin requirements, energy expenditure, and glucose levels at very high altitude in relation to acute mountain sickness (AMS) symptoms in ind

  1. Increased insulin requirements during exercise at very high altitude in type 1 diabetes

    NARCIS (Netherlands)

    Mol, P. De; Vries, S.T. de; Koning, E.J. de; Gans, R.O.; Tack, C.J.J.; Bilo, H.J.

    2011-01-01

    OBJECTIVE: Safe, very high altitude trekking in subjects with type 1 diabetes requires understanding of glucose regulation at high altitude. We investigated insulin requirements, energy expenditure, and glucose levels at very high altitude in relation to acute mountain sickness (AMS) symptoms in

  2. Increased insulin requirements during exercise at very high altitude in type 1 diabetes

    NARCIS (Netherlands)

    de Mol, Pieter; de Vries, Suzanna T.; de Koning, Eelco J. P.; Gans, Rijk O. B.; Tack, Cees J.; Bilo, Henk J. G.

    OBJECTIVE-Safe, very high altitude trekking in subjects with type 1 diabetes requires understanding of glucose regulation at high altitude. We investigated insulin requirements, energy expenditure, and glucose levels at very high altitude in relation to acute mountain sickness (AMS) symptoms in

  3. Structural and functional changes of the human macula during acute exposure to high altitude.

    Directory of Open Access Journals (Sweden)

    M Dominik Fischer

    Full Text Available BACKGROUND: This study aimed to quantify structural and functional changes at the macula during acute exposure to high altitude and to assess their structure/function relationship. This work is related to the Tuebingen High Altitude Ophthalmology (THAO study. METHODOLOGY/PRINCIPAL FINDINGS: Spectral domain optical coherence tomography and microperimetry were used to quantify changes of central retinal structure and function in 14 healthy subjects during acute exposure to high altitude (4559 m. High-resolution volume scans and fundus-controlled microperimetry of the posterior pole were performed in addition to best-corrected visual acuity (BCVA measurements and assessment of acute mountain sickness. Analysis of measurements at altitude vs. baseline revealed increased total retinal thickness (TRT in all four outer ETDRS grid subfields during acute altitude exposure (TRT(outer = 2.80 ± 1.00 μm; mean change ± 95%CI. This change was inverted towards the inner four subfields (TRT(inner = -1.89 ± 0.97 μm with significant reduction of TRT in the fovea (TRT(foveal = -6.62 ± 0.90 μm at altitude. BCVA revealed no significant difference compared to baseline (0.06 ± 0.08 logMAR. Microperimetry showed stable mean sensitivity in all but the foveal subfield (MS(foveal = -1.12 ± 0.68 dB. At baseline recordings before and >2 weeks after high altitude exposure, all subjects showed equal levels with no sign of persisting structural or functional sequels. CONCLUSIONS/SIGNIFICANCE: During acute exposure to high altitude central retinal thickness is subject to minor, yet statistically significant changes. These alterations describe a function of eccentricity with an increase in regions with relatively higher retinal nerve fiber content and vascular arcades. However, these changes did not correlate with measures of central retinal function or acute mountain sickness. For the first time a quantitative approach has been used to assess these changes during acute

  4. Structural and Functional Changes of the Human Macula during Acute Exposure to High Altitude

    Science.gov (United States)

    Fischer, M. Dominik; Willmann, Gabriel; Schatz, Andreas; Schommer, Kai; Zhour, Ahmad; Zrenner, Eberhart; Bartz-Schmidt, Karl U.; Gekeler, Florian

    2012-01-01

    Background This study aimed to quantify structural and functional changes at the macula during acute exposure to high altitude and to assess their structure/function relationship. This work is related to the Tuebingen High Altitude Ophthalmology (THAO) study. Methodology/Principal Findings Spectral domain optical coherence tomography and microperimetry were used to quantify changes of central retinal structure and function in 14 healthy subjects during acute exposure to high altitude (4559 m). High-resolution volume scans and fundus-controlled microperimetry of the posterior pole were performed in addition to best-corrected visual acuity (BCVA) measurements and assessment of acute mountain sickness. Analysis of measurements at altitude vs. baseline revealed increased total retinal thickness (TRT) in all four outer ETDRS grid subfields during acute altitude exposure (TRTouter = 2.80±1.00 μm; mean change±95%CI). This change was inverted towards the inner four subfields (TRTinner = −1.89±0.97 μm) with significant reduction of TRT in the fovea (TRTfoveal = −6.62±0.90 μm) at altitude. BCVA revealed no significant difference compared to baseline (0.06±0.08 logMAR). Microperimetry showed stable mean sensitivity in all but the foveal subfield (MSfoveal = −1.12±0.68 dB). At baseline recordings before and >2 weeks after high altitude exposure, all subjects showed equal levels with no sign of persisting structural or functional sequels. Conclusions/Significance During acute exposure to high altitude central retinal thickness is subject to minor, yet statistically significant changes. These alterations describe a function of eccentricity with an increase in regions with relatively higher retinal nerve fiber content and vascular arcades. However, these changes did not correlate with measures of central retinal function or acute mountain sickness. For the first time a quantitative approach has been used to assess these changes during acute, non

  5. Ergogenic properties of metformin in simulated high altitude.

    Science.gov (United States)

    Scalzo, Rebecca L; Paris, Hunter L; Binns, Scott E; Davis, Janelle L; Beals, Joseph W; Melby, Christopher L; Luckasen, Gary J; Hickey, Matthew S; Miller, Benjamin F; Hamilton, Karyn L; Bell, Christopher

    2017-07-01

    Metformin augments glucose/glycogen regulation and may acutely promote fatigue resistance during high-intensity exercise. In hypobaric environments, such as high altitude, the important contribution of carbohydrates to physiological function is accentuated as glucose/glycogen dependence is increased. Because hypoxia/hypobaria decreases insulin sensitivity, replenishing skeletal muscle glycogen in high altitude becomes challenging and subsequent physical performance may be compromised. We hypothesized that in conditions where glycogen repletion was critical to physical outcomes, metformin would attenuate hypoxia-mediated decrements in exercise performance. On three separate randomly ordered occasions, 13 healthy men performed glycogen-depleting exercise and ingested a low-carbohydrate dinner (1200 kcals, metformin (500 mg BID) was consumed 3 days prior to each hypoxia visit. Subjects completed a 12.5 km cycle ergometer time trial 3.5 hours following breakfast. Hypoxia decreased resting and exercise oxyhemoglobin saturation (Pmetformin affected the glucose response to breakfast (P=.977), however, compared with placebo, metformin lowered insulin concentration in hypoxia 45 minutes after breakfast (64.1±6.6 μU/mL vs 48.5±7.8 μU/mL; mean±SE; Pmetformin (+81%; P=.006), but not in hypoxia with placebo (+27%; P=.167). Hypoxia decreased time trial performance compared with normoxia (Pmetformin (+1.6±0.3 minutes). These results indicate that metformin promotes glycogen synthesis but not endurance exercise performance in healthy men exposed to simulated high altitude. © 2017 John Wiley & Sons Australia, Ltd.

  6. A comparative high-altitude meteorological analysis from three catchments in the Nepalese Himalaya

    NARCIS (Netherlands)

    Shea, J. M.; Wagnon, P.; Immerzeel, W. W.; Biron, R.; Brun, F.; Pellicciotti, F.

    2015-01-01

    Meteorological studies in high-mountain environments form the basis of our understanding of catchment hydrology and glacier accumulation and melt processes, yet high-altitude (>4000 m above sea level, asl) observatories are rare. This research presents meteorological data recorded between December 2

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

    Directory of Open Access Journals (Sweden)

    Emma eDespland

    2014-09-01

    Full Text Available The butterfly fauna of the high-altitude desert of Northern Chile, though depauperate, shows high endemism, is poorly known and is of considerable conservation concern. This study surveys butterflies along the Andean slope between 2400 and 500 m asl (prepuna, puna and Andean steppe habitats as well as in high and low altitude wetlands and in the neoriparian vegetation of agricultural sites. We also include historical sightings from museum records. We compare abundances between altitudes, between natural and impacted sites, as well as between two sampling years with different precipitation regimes. The results confirm high altitudinal turnover and show greatest similarity between wetland and slope faunas at similar altitudes. Results also underscore vulnerability to weather fluctuations, particularly in the more arid low-altitude sites, where abundances were much lower in the low precipitation sampling season and several species were not observed at all. Finally, we show that some species have shifted to the neoriparian vegetation of the agricultural landscape, whereas others were only observed in less impacted habitats dominated by native plants. These results suggest that acclimation to novel habitats depends on larval host plant use. The traditional agricultural environment can provide habitat for many, but not all, native butterfly species, but an estimation of the value of these habitats requires better understanding of butterfly life-history strategies and relationships with host plants.

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

    Science.gov (United States)

    Despland, Emma

    2014-01-01

    The butterfly fauna of the high-altitude desert of Northern Chile, though depauperate, shows high endemism, is poorly known and is of considerable conservation concern. This study surveys butterflies along the Andean slope between 2400 and 5000 m asl (prepuna, puna and Andean steppe habitats) as well as in high and low-altitude wetlands and in the neoriparian vegetation of agricultural sites. We also include historical sightings from museum records. We compare abundances between altitudes, between natural and impacted sites, as well as between two sampling years with different precipitation regimes. The results confirm high altitudinal turnover and show greatest similarity between wetland and slope faunas at similar altitudes. Results also underscore vulnerability to weather fluctuations, particularly in the more arid low-altitude sites, where abundances were much lower in the low precipitation sampling season and several species were not observed at all. Finally, we show that some species have shifted to the neoriparian vegetation of the agricultural landscape, whereas others were only observed in less impacted habitats dominated by native plants. These results suggest that acclimation to novel habitats depends on larval host plant use. The traditional agricultural environment can provide habitat for many, but not all, native butterfly species, but an estimation of the value of these habitats requires better understanding of butterfly life history strategies and relationships with host plants. PMID:25309583

  9. Flow separation in rocket nozzles under high altitude condition

    Science.gov (United States)

    Stark, R.; Génin, C.

    2017-01-01

    The knowledge of flow separation in rocket nozzles is crucial for rocket engine design and optimum performance. Typically, flow separation is studied under sea-level conditions. However, this disregards the change of the ambient density during ascent of a launcher. The ambient flow properties are an important factor concerning the design of altitude-adaptive rocket nozzles like the dual bell nozzle. For this reason an experimental study was carried out to study the influence of the ambient density on flow separation within conventional nozzles.

  10. Carbonic anhydrase activity in the red blood cells of sea level and high altitude natives.

    Science.gov (United States)

    Gamboa, J; Caceda, R; Gamboa, A; Monge-C, C

    2000-01-01

    Red blood cell carbonic anhydrase (CA) activity has not been studied in high altitude natives. Because CA is an intraerythocytic enzyme and high altitude natives are polycythemic, it is important to know if the activity of CA per red cell volume is different from that of their sea level counterparts. Blood was collected from healthy subjects living in Lima (150m) and from twelve subjects from Cerro de Pasco (4330m), and hematocrit and carbonic anhydrase activity were measured. As expected, the high altitude natives had significantly higher hematocrits than the sea level controls (p = 0.0002). No difference in the CA activity per milliliter of red cells was found between the two populations. There was no correlation between the hematocrit and CA activity.

  11. Magnetic Monopole Search at high altitude with the SLIM experiment

    CERN Document Server

    Balestra, S; Cozzi, M; Errico, M; Fabbri, F; Giacomelli, G; Giacomelli, R; Giorgini, M; Kumar, A; Manzoor, S; McDonald, J; Mandrioli, G; Marcellini, S; Margiotta, A; Medinaceli, E; Patrizii, L; Pinfold, J L; Popa, V; Qureshi, I E; Saavedra, O; Sahnoun, Z; Sirri, G; Spurio, M; Togo, V; Velarde, A; Zanini, A

    2008-01-01

    The SLIM experiment was a large array of nuclear track detectors located at the Chacaltaya high altitude Laboratory (5230 m a.s.l.). The detector was in particular sensitive to Intermediate Mass Magnetic Monopoles, with masses 10^5 < M <10^{12} GeV. From the analysis of the full detector exposed for more than 4 years a flux upper limit of 1.3 x 10^{-15} cm^{-2} s^{-1} sr^{-1} for downgoing fast Intermediate Mass Monopoles was established at the 90% C.L.

  12. Science 101: Why Does It Take Longer to Boil Potatoes at High Altitudes?

    Science.gov (United States)

    Robertson, Bill

    2017-01-01

    Why Does It Take Longer to Boil Potatoes at High Altitudes? This column provides background science information for elementary teachers. This month's issue looks at why water boils at different temperatures at different altitudes.

  13. A Possible High Altitude High Energy Gamma Ray Observatory in India

    CERN Document Server

    Cowsik, R; Chitnis, V R; Acharya, B S; Vishwanath, P R

    2001-01-01

    Recently an Indian Astronomical Observatory has been set up at Hanle (32$^\\circ$ 46$^\\prime$ 46$^{\\prime\\prime}$ N, 78$^\\circ$ 57$^\\prime$ 51$^{\\prime\\prime}$ E, 4515m amsl) situated in the high altitude cold desert in the Himalayas. The Observatory has 2-m aperture optical-infrared telescope, recently built by the Indian Institute of Astrophysics. We have carried out systematic simulations for this observation level to study the nature of \\v{C}erenkov light pool generated by gamma ray and proton primaries incident vertically at the top of the atmosphere. The differences in the shape of the lateral distributions of \\v{C}erenkov light with respect to that at lower altitudes is striking. This arises primarily due to the proximity of the shower maximum to the observation site. The limited lateral spread of the \\v{C}erenkov light pool and near 90% atmospheric transmission at this high altitude location makes it an ideal site for a gamma ray observatory. This results in a decrease in the gamma ray energy threshold...

  14. Identifying positive selection candidate loci for high-altitude adaptation in Andean populations

    Directory of Open Access Journals (Sweden)

    Bigham Abigail W

    2009-12-01

    Full Text Available Abstract High-altitude environments (>2,500 m provide scientists with a natural laboratory to study the physiological and genetic effects of low ambient oxygen tension on human populations. One approach to understanding how life at high altitude has affected human metabolism is to survey genome-wide datasets for signatures of natural selection. In this work, we report on a study to identify selection-nominated candidate genes involved in adaptation to hypoxia in one highland group, Andeans from the South American Altiplano. We analysed dense microarray genotype data using four test statistics that detect departures from neutrality. Using a candidate gene, single nucleotide polymorphism-based approach, we identified genes exhibiting preliminary evidence of recent genetic adaptation in this population. These included genes that are part of the hypoxia-inducible transcription factor (HIF pathway, a biochemical pathway involved in oxygen homeostasis, as well as three other genomic regions previously not known to be associated with high-altitude phenotypes. In addition to identifying selection-nominated candidate genes, we also tested whether the HIF pathway shows evidence of natural selection. Our results indicate that the genes of this biochemical pathway as a group show no evidence of having evolved in response to hypoxia in Andeans. Results from particular HIF-targeted genes, however, suggest that genes in this pathway could play a role in Andean adaptation to high altitude, even if the pathway as a whole does not show higher relative rates of evolution. These data suggest a genetic role in high-altitude adaptation and provide a basis for genotype/phenotype association studies that are necessary to confirm the role of putative natural selection candidate genes and gene regions in adaptation to altitude.

  15. Experimental study on thermal balance performance of naturally aspirated diesel engine at high altitude (low air pressure)%自然吸气柴油机高海拔(低气压)热平衡试验研究

    Institute of Scientific and Technical Information of China (English)

    董素荣; 许翔; 任晓江; 关立哲; 郑智; 刘瑞林

    2011-01-01

    基于内燃机高海拔(低气压)热平衡模拟试验台,对某型内燃叉车自然吸气柴油机进行了热平衡高原模拟试验,研究了柴油机燃烧放热量分配、冷却液温度以及排气温度等随海拔高度(大气压力)的变化规律.结果表明:随着海拔的升高,转化为有效功的热量、冷却水散热量以及排气带走的热量均不断下降,柴油机不完全燃烧造成的热损失、机体散失的热量以及其他热损失所占比重不断增加;与平原相比,海拔5 000 m时,转化为有效功的热量平均下降了13.79%,冷却水散热量平均下降了2.27%,排气带走的热量平均下降了14.4%,发动机的热平衡性能与平原相比发生了较大的变化.%The thermal balance performance of naturally aspirated forklift diesel engine at different altitudes was studied on the engine thermal balance test bed for simulating with high altitude (low air pressure). Influence of atmospheric pressure on the heat distribution, coolant temperature and exhaust gas temperature were analyzed. Results show that thermal changed into usable power, thermal carried by cooling water and exhaust gas decreased with the increase of altitude. On the contrary, the heat loss due to incomplete combustion increased with the increase of altitude. Compared with that at 5 000 m altitude, thermal changed into usable power decreased by 13. 79%; thermal carried by cooling water decreased by 2. 27%; thermal carried by exhaust air decreased by 14.4%. The thermal balance performance at high altitude is different from the performance at sea level.

  16. Objective criteria for diagnosing high altitude pulmonary edema in acclimatized patients at altitudes between 2700 m and 3500 m

    Science.gov (United States)

    Chawla, Anuj; Tripathi, K.K.

    2015-01-01

    Background The criteria used for diagnosing high altitude illnesses are largely based on Western literature. This study was undertaken to define objective, simple and reliable diagnostic criteria for high altitude pulmonary edema (HAPE) in Indian soldiers at altitudes between 2700 m and 3500 m. Methods Clinical data of 235 cases of HAPE that occurred between 2700 m and 3500 m were analysed. Receiver operator characteristic (ROC) curve analysis was used to select simple clinical parameters suitable for the diagnosis of HAPE at peripheral medical facilities. Cut-off values and their reliability for the diagnosis of HAPE were defined. Results HAPE occurred 2.8 ± 2.2 days after arrival at altitudes between 2700 m and 3500 m. Breathlessness, cough, chest discomfort and headache were the commonest symptoms. Low pulse oximetry (SPO2) values than normal for this altitude were seen in 89% of patients. ROC analysis of clinical parameters identified a heart rate more than 95 beats per minute (bpm), respiratory rate more than 21 per minute and SPO2 less than 86% while breathing ambient air at this altitude as diagnostic of HAPE. The sensitivity and specificity of these cut-offs was 0.66, 0.83 and 0.82 and 0.94, 0.95 and 0.93 respectively. Conclusion A heart rate of more than 95 bpm, respiratory rate more than 21 per minute and SPO2 less than 86% breathing room air in individuals complaining of breathlessness, cough, chest discomfort or headache within the first 5 days of arrival at altitudes between 2700 m and 3500 m is highly suggestive of HAPE. PMID:26663962

  17. Association between Serum Interleukin-17A Level and High-Altitude Deacclimatization Syndrome.

    Science.gov (United States)

    He, Binfeng; Li, Hongli; Hu, Mingdong; Dong, Weijie; Wei, Zhenghua; Li, Jin; Yao, Wei; Guo, Xiaolan

    2016-01-01

    High-altitude deacclimatization syndrome (HADAS) is emerging as a severe public health issue that threatens the quality of life of individuals who return to lower altitude from high altitude. In this study, we measured serum levels of SOD, MDA, IL-17A, IL-10, TNF-α, and HADAS score in HADAS subjects at baseline and 50th and 100th days and to evaluate the relationship between interleukins, including IL-17A, and HADAS. Our data showed that and the serum IL-17A levels and HADAS score decreased over time in the HADAS group, and serum IL-17A levels were significantly higher in the HADAS group at baseline and 50th day compared with controls (p HADAS subjects compared with controls (p HADAS incidence and severity (p HADAS incidence than serum levels of IL-17A or IL-10 alone. These data suggest that serum levels of IL-17A are a novel predictive index of HADAS.

  18. A gloss of Chronic Hypoxia in normal and diseased individuals at high altitude

    Institute of Scientific and Technical Information of China (English)

    Zubieta-Castillo,G.; Zubieta-Calleja,G.R.; Zubieta-Calleja L.

    2004-01-01

    @@ Introduction Millenary populations that live at high altitude in different continents like Asia (1) and South America (8), have endured biological adaptation in very adverse environmental conditions, of which to our understanding, paradoxically, chronic hypoxia is the most tolerable. Patients with pulmonary diseases at high altitude tolerate tissue hypoxia with an arterial tension (PaO2) even as low as 30 mmHg. Current scientific knowledge has made progress in many areas, clarifying many doubts, however due to preconception and lack of broad social studies chronic hypoxia is still not fully understood. Beings that inhabit different areas of the planet earth have lived under a variety of different hostile conditions: intense cold in the polar regions,intense heat in Africa and in the Middle East desserts,great pressure in the depth of the oceans, intense darkness of the caves and naturally the hypoxia of extreme altitudes.

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

    Science.gov (United States)

    Feiereisen, William J.; Venkatapathy, Ethiraj

    1988-01-01

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

  20. High resolution spectroscopy from low altitude satellites. [gamma ray astronomy

    Science.gov (United States)

    Nakano, G. H.; Imhof, W. L.

    1978-01-01

    The P 78 1 satellite to be placed in a synchronous polar orbit at an altitude of 550-660 km will carry two identical high resolution spectrometers each consisting of a single (approximately 85 cc) intrinsic germanium IGE detector. The payload also includes a pair of phoswitch scintillators, an array of CdTe detectors and several particle detectors, all of which are mounted on the wheel of the satellite. The intrinsic high purity IGE detectors receive cooling from two Stirling cycle refrigerators and facilitate the assembly of large and complex detector arrays planned for the next generation of high sensitivity instruments such as those planned for the gamma ray observatory. The major subsystems of the spectrometer are discussed as well as its capabilities.

  1. Persistence of chironomids in metal polluted Andean high altitude streams: does melanin play a role?

    NARCIS (Netherlands)

    Loayza Muro, R.A.; Marticorena-Ruíz, J.K.; Palomino, E.J.; Merritt, C.; de Baat, M.L.; van Gemert, M.; Verweij, R.A.; Kraak, M.H.S.; Admiraal, W.

    2013-01-01

    In high altitude Andean streams an intense solar radiation and coinciding metal pollution allow the persistence of only a few specialized taxa, including chironomids. The aim of the present study was therefore to determine the mechanisms underlying the persistence of chironomids under these multiple

  2. Persistence of chironomids in metal polluted Andean high altitude streams: does melanin play a role?

    NARCIS (Netherlands)

    Loayza Muro, R.A.; Marticorena-Ruíz, J.K.; Palomino, E.J.; Merritt, C.; de Baat, M.L.; van Gemert, M.; Verweij, R.A.; Kraak, M.H.S.; Admiraal, W.

    2013-01-01

    In high altitude Andean streams an intense solar radiation and coinciding metal pollution allow the persistence of only a few specialized taxa, including chironomids. The aim of the present study was therefore to determine the mechanisms underlying the persistence of chironomids under these multiple

  3. Comments on “High Altitude Pulmonary Edema in an Experienced Mountaineer. Possible Genetic Predisposition”

    Directory of Open Access Journals (Sweden)

    Gaurav Sikri

    2015-10-01

    Full Text Available We appreciate the letter to the editor and are pleased to respond regarding our recent case study regarding high altitude pulmonary edema in an experienced mountaineer. The letter raises some valid questions regarding our treatment decisions. With this, as with most emergency department (ED patients, it must be understood that the initial treatment reflected the breadth of our differential diagnosis.

  4. Radiation Safety Issues in High Altitude Commercial Aircraft

    Science.gov (United States)

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

    1995-01-01

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

  5. Increased choroidal thickness in patient with high-altitude retinopathy

    Directory of Open Access Journals (Sweden)

    Kyoko Hirukawa-Nakayama

    2014-01-01

    Full Text Available We report a case of high-altitude retinopathy with increased choroidal thickness detected by spectral-domain optical coherence tomography (SD-OCT. A 36-year-old Japanese man developed an acute vision decrease in his left eye after he had trekked at an altitude of 4600 m in Tibet for 1 week. His visual acuity was 20/20 OD and 20/200 OS with refractive errors of − 0.25 diopters (D OD and − 0.50 D OS 3 weeks after the onset of the visual decrease. Funduscopic examinations revealed multiple intraretinal hemorrhages bilaterally and a macular hemorrhage in the left eye. SD-OCT showed that the thickness of choroidal layer at the fovea was 530 μm OD and 490 μm OS which is thicker than that in normal subjects of approximately 300 μm. We suggest that the increase in the retinal blood flow under hypoxic conditions may be associated with an increase in the choroidal blood flow resulting in an increase in choroidal thickness.

  6. Scientific verification of High Altitude Water Cherenkov observatory

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-04-01

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

  7. Physical Body Impact After High Altitude Bail-out

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaopeng; GUAN Huanwen; ZHUO Congshan; FENG Wenchun; ZHONG Chengwen

    2011-01-01

    In most of the emergency circumstances, the aircrew leaves the aircraft under unsatisfied conditions, such as too high relative velocity to the ambient air or Iow partial oxygen pressure. The aircrew must pass through this area as quickly as possible before opening the parachute safely, viz., free-fall. Numerical simulations are conducted in this paper to explore the major characteristics of the aircrew free-fall process by using a commercial computational fluid dynamic (CFD) software, FLUENT. Coupled with the classical pressure-altitude and temperature-altitude relations, Navier-Stokes (N-S) equations for compressible flow are solved by using finite volume method. The body velocity and the attitude are predicted with six-degree of freedom (6DOF) module. The evolution of velocities, including horizontal, vertical components and angular velocity, is obtained. It is also analyzed further according to the particle kinetic theories. It is validated that the theories can predict the process qualitatively well with a modified drag effect, which mainly stems from the velocity pressure. An empirical modification factor is proposed according to the fitting results.

  8. Scientific verification of High Altitude Water Cherenkov observatory

    Science.gov (United States)

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

    2014-04-01

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

  9. Elevated Suicide Rates at High Altitude: Sociodemographic and Health Issues May Be to Blame

    Science.gov (United States)

    Betz, Marian E.; Valley, Morgan A.; Lowenstein, Steven R.; Hedegaard, Holly; Thomas, Deborah; Stallones, Lorann; Honigman, Benjamin

    2011-01-01

    Suicide rates are higher at high altitudes; some hypothesize that hypoxia is the cause. We examined 8,871 suicides recorded in 2006 in 15 states by the National Violent Death Reporting System, with the victim's home county altitude determined from the National Elevation Dataset through FIPS code matching. We grouped cases by altitude (low less…

  10. Gravity waves and high-altitude CO$_2$ ice cloud formation in the Martian atmosphere

    CERN Document Server

    Yiğit, Erdal; Hartogh, Paul

    2015-01-01

    We present the first general circulation model simulations that quantify and reproduce patches of extremely cold air required for CO$_2$ condensation and cloud formation in the Martian mesosphere. They are created by subgrid-scale gravity waves (GWs) accounted for in the model with the interactively implemented spectral parameterization. Distributions of GW-induced temperature fluctuations and occurrences of supersaturation conditions are in a good agreement with observations of high-altitude CO$_2$ ice clouds. Our study confirms the key role of GWs in facilitating CO$_2$ cloud formation, discusses their tidal modulation, and predicts clouds at altitudes higher than have been observed to date.

  11. Thermoelectric Energy Conversion Technology for High-Altitude Airships

    Science.gov (United States)

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

    2011-01-01

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

  12. Radiation Physics for Space and High Altitude Air Travel

    Science.gov (United States)

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

    2000-01-01

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

  13. Centurion solar-powered high-altitude aircraft in flight

    Science.gov (United States)

    1998-01-01

    Since 1980 AeroVironment, Inc. (founded in 1971 by the ultra-light airplane innovator--Dr. Paul MacCready) has been experimenting with solar-powered aircraft, often in conjunction with the NASA Dryden Flight Research Center, Edwards, California. Thus far, AeroVironment, now headquartered in Monrovia, California, has achieved several altitude records with its Solar Challenger, Pathfinder, and Pathfinder-Plus aircraft. It expects to exceed these records with the newer and larger solar-powered Centurion and its successors the Centelios and Helios vehicles, in the NASA Environmental Research Aircraft and Sensor Technology (ERAST) program. The Centurion is a lightweight, solar-powered, remotely piloted flying wing aircraft that is demonstrating the technology of applying solar power for long-duration, high-altitude flight. It is considered to be a prototype technology demonstrator for a future fleet of solar-powered aircraft that could stay airborne for weeks or months on scientific sampling and imaging missions or while serving as telecommunications relay platforms. Although it shares many of the design concepts of the Pathfinder, the Centurion has a wingspan of 206 feet, more than twice the 98-foot span of the original Pathfinder and 70-percent longer than the Pathfinder-Plus' 121-foot span. At the same time, Centurion maintains the 8-foot chord (front to rear distance) of the Pathfinder wing, giving the wing an aspect ratio (length-to-chord) of 26 to 1. Other visible changes from its predecessor include a modified wing airfoil designed for flight at extreme altitude and four underwing pods to support its landing gear and electronic systems (compared with two such pods on the Pathfinder). The flexible wing is primarily fabricated from carbon fiber, graphite epoxy composites, and kevlar. It is built in five sections, a 44-foot-long center section and middle and outer sections just over 40 feet long. All five sections have an identical thickness--12 percent of the chord

  14. Reflections on the VI World Congress of Mountain Medicine and High-Altitude Physiology in Xining and Lhasa, August 2004

    Institute of Scientific and Technical Information of China (English)

    John B. West

    2005-01-01

    @@ The VI World Congress of Mountain Medicine and High-Altitude Physiology in Xining and Lhasa which was held in August 2004 was a landmark event in the burgeoning area of high-altitude life studies. These congresses have taken place every two years, often in exotic venues, and always related to geographical areas of interest in high-altitude medicine. The first five high congresses were held in La Paz, Bolivia; Cusco, Peru; Matsumoto, Japan; Arica, Chile; and Barcelona, Spain. As can be seen from these venues, the previous congresses were located near the South American Andes, the Japanese Alps, and the European Pyrenees and Alps.

  15. Prevalence of Hypertension in a Tribal Land Locked Population at High Altitude

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Raina

    2016-01-01

    Full Text Available Introduction. Extensive pubmed search reveals paucity of data on prevalence of hypertension in tribal population at high altitude. The data is all the more scarce from our part of India. Studies among tribal populations at high altitudes provide an interesting epidemiological window to study human evolution and adaptation to hypobaric hypoxia. Material and Methods. 401 participants above the age of 20 years were evaluated for blood pressure using a stratified simple random technique among villages located at high altitude. Results. Out of a total of 401 individuals studied 43 (males: 35; females: 8 were identified as hypertensive yielding a crude prevalence of 10.7%. The prevalence was higher in males (35/270; 12.9% as compared to females (8/131; 6%. Prevalence was the highest in the age group of 30–39 among males (16/35; 45.7% while it was the highest in the age group of 40–49 among females (7/8; 87%. Conclusions. Prevalence of 10.5% is noteworthy when interpreted in light of prevalence of hypertension in general population especially if hypobaric hypoxia is considered to have a protective effect on blood pressure in high altitude native populations.

  16. Prevalence of Hypertension in a Tribal Land Locked Population at High Altitude

    Science.gov (United States)

    Raina, Sunil Kumar; Chander, Vishav; Prasher, Chaman Lal; Raina, Sujeet

    2016-01-01

    Introduction. Extensive pubmed search reveals paucity of data on prevalence of hypertension in tribal population at high altitude. The data is all the more scarce from our part of India. Studies among tribal populations at high altitudes provide an interesting epidemiological window to study human evolution and adaptation to hypobaric hypoxia. Material and Methods. 401 participants above the age of 20 years were evaluated for blood pressure using a stratified simple random technique among villages located at high altitude. Results. Out of a total of 401 individuals studied 43 (males: 35; females: 8) were identified as hypertensive yielding a crude prevalence of 10.7%. The prevalence was higher in males (35/270; 12.9%) as compared to females (8/131; 6%). Prevalence was the highest in the age group of 30–39 among males (16/35; 45.7%) while it was the highest in the age group of 40–49 among females (7/8; 87%). Conclusions. Prevalence of 10.5% is noteworthy when interpreted in light of prevalence of hypertension in general population especially if hypobaric hypoxia is considered to have a protective effect on blood pressure in high altitude native populations. PMID:26989560

  17. Renin and aldosterone at high altitude in man.

    Science.gov (United States)

    Keynes, R J; Smith, G W; Slater, J D; Brown, M M; Brown, S E; Payne, N N; Jowett, T P; Monge, C C

    1982-01-01

    Measurements have been made of hormonal changes relevant to salt and water balance during prolonged exposure to hypoxia to improve our understanding of the syndrome of acute mountain sickness. We have attempted to delineate the detailed inter-relationships between the renin-aldosterone and the vasopressin systems by a metabolically controlled study, involving an orthostatic stress (45 degrees head-up tilt) and an injection of a standard dose of ACTH to test adrenal responsiveness. Three Caucasian medical students underwent a 7-day equilibration at 150 m (Lima, Peru), followed by a 6-day sojourn at 4350 m (Cerro de Pasco, Peru) and a final 7 days at 150 m. Measurements were made of sodium and potassium balance, body weight and the 24-h renal excretion of vasopressin, cortisol and aldosterone 18-glucuronide. These variables showed little change, except for that of aldosterone 18-glucuronide, which fell sharply at altitude and rebounded even more sharply on return to sea level. At altitude, basal plasma levels of renin activity and aldosterone fell, and the response to orthostasis was attenuated, but the fall of plasma renin activity, as compared to plasma aldosterone, was delayed; on return to sea level this dissociation was exacerbated with the return of normal renin responsiveness lagging behind that of aldosterone. We suggest that unknown factors which dissociate the orthodox renin-aldosterone relationship, other than the activity of the angiotensin I-converting enzyme, are operative on exposure to hypoxia.

  18. Incidence of high altitude pulmonary edema in low-landers during re-exposure to high altitude after a sojourn in the plains

    Science.gov (United States)

    Apte, C.V.; Tomar, R.K.S.; Sharma, D.

    2015-01-01

    Background There is uncertainty whether acclimatized low-landers who return to high altitude after a sojourn at low altitude have a higher incidence of pulmonary edema than during the first exposure to high altitude. Methods This was a prospective cohort study consisting of men ascending to 3400 m by road (N = 1003) or by air (N = 4178). The study compared the incidence of high altitude pulmonary edema during first exposure vs the incidence during re-exposure in each of these cohorts. Results Pulmonary edema occurred in 13 of the 4178 entries by air (Incidence: 0.31%, 95% CI: 0.18%–0.53%). The incidence during first exposure was 0.18% (0.05%–0.66%) and 0.36% (0.2%–0.64%) during re-exposure (Fisher Exact Test for differences in the incidence (two-tailed) p = 0.534). The relative risk for the re-exposure cohort was 1.95 (95% CI, 0.43%–8.80%). Pulmonary edema occurred in 3 of the 1003 road entrants (Incidence: 0.30%, 95% CI: 0.08%–0.95%). All three cases occurred in the re-exposure cohort. Conclusion The large overlap of confidence intervals between incidence during first exposure and re-exposure; the nature of the confidence interval of the relative risk; and the result of the Fisher exact test, all suggest that this difference in incidence could have occurred purely by chance. We did not find evidence for a significantly higher incidence of HAPE during re-entry to HA after a sojourn in the plains. PMID:26288488

  19. AltitudeOmics: The Basic Biology of Human Acclimatization to High Altitude. Addendum

    Science.gov (United States)

    2014-09-01

    After obtaining written consent, physical exams and the Army Physical Fitness Test (push-ups, sit-ups, and a 3.2-km run) were performed to verify health...imposed by the MFVL. Membrane Excitability and Contractile Function M-waves. As a measure of membrane excitability we exam - ined pre- vs. postexercise...Rose MS, Forte VA, Jr., Young PM, and Cymerman A. Effect of caffeine on submaximal exercise performance at altitude. Aviat Space Environ Med 65: 539

  20. AltitudeOmics: The Basic Biology of Human Acclimatization to High Altitude

    Science.gov (United States)

    2013-09-01

    met the limit imposed by the MFVL. Membrane Excitability and Contractile Function M-waves. As a measure of membrane excitability we exam - ined pre...least 3 h postprandial, and avoided strenuous exercise in the 48 h preceding each trial. They also refrained from caffeine for 12 h before each test...traveled to altitudes > 1,000 m in the past 3 months. After obtaining written consent, physical exams and the Army Physical Fitness Test (push ups

  1. Effect of high altitude on sensitivity to the taste of phenylthiocarbamide

    Science.gov (United States)

    Singh, S. B.; Chatterjee, A.; Panjwani, U.; Yadav, D. K.; Selvamurthy, W.; Sharma, K. N.

    Sensitivity to the taste of phenylthiocarbamide (PTC) was studied using the Harris-Kalmus method in healthy human volunteers at sea level and then subsequently at an altitude of 3500 m over a period of 3 weeks, after which they were brought back to sea level. Blood sugar, insulin and blood cortisol levels were estimated weekly. The results indicated that, out of 51 subjects studied, 26 (55%) were PTC tasters at sea level. Eight of those unable to taste PTC at sea level tested as tasters at high altitude, and 2 of them reverted to being non-tasters on return to sea level. In the blood, an increase in cortisol and blood insulin levels was seen without any significant change in sugar levels. All the changes recorded at high altitude tended to return to basal values after re-induction to sea level. The study suggests that high-altitude hypoxia in some way, possibly involving changes in hormonal profile among other factors, causes an alteration in sensitivity to the taste of PTC, resulting in some of the individuals shifting to lower PTC sensitivity.

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

    Directory of Open Access Journals (Sweden)

    Flavio Araripe D'Oliveira

    2016-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-11

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

  4. STEERABLE ANTENNAS MOVEMENT COMPENSATION FOR HIGH ALTITUDE PLATFORM

    Institute of Scientific and Technical Information of China (English)

    Wang Zhenyong; Liu Xiaowei; Li Zhuoshi

    2011-01-01

    High Altitude Platform (HAP) must compensate for relative motion with respect to the ground because of the stratosphere complexity,which is important to guarantee Quality of Service(QoS) in intended coverage area.With analysis on HAP movement models for predicting the geographical coverage in the cases of shift horizontally and vertically,yaw,roll and pitch,the mechanisms of steerable antennas movement compensation are investigated.The mechanism is applied to a scenario of 127 cell architecture,with a cell cluster size of four.By the simulation results of Carrier to Interference Ratio (CIR),the steerable antenna movement compensation mechanism decrease influence of HAP movement and guarantee effective coverage of the service area.

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

    Science.gov (United States)

    Weisgarber, Thomas

    2013-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Pandey P

    2014-05-01

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

  7. Development of unmanned aerial vehicle (UAV) based high altitude balloon (HAB) platform for active aerosol sampling

    Science.gov (United States)

    Lateran, S.; Sedan, M. F.; Harithuddin, A. S. M.; Azrad, S.

    2016-10-01

    The knowledge on the abundance and diversity of the minute particles or aerosols in the earth's stratosphere is still in its infancy as aerosol sampling at high-altitude still possess a lot of challenges. Thus far, high-altitude aerosol sampling has been conducted mostly using manned flights, which requires enormous financial and logistical resources. There had been researches for the utilisation of high altitude balloon (HAB) for active and passive aerosol samplings within the stratosphere. However, the gathered samples in the payload were either brought down by controlling the balloon air pressure or were just dropped with a parachute to slow the descend speed in order to reduce the impact upon landing. In most cases, the drop location of the sample are unfavorable such as in the middle of the sea, dense foliage, etc. Hence a system that can actively sample aerosols at high-altitude and improve the delivery method in terms of quality and reliability using unmanned aerial vehicle (UAV) is designed and tested in this study.

  8. Oxygen enrichment and its application to life support systems for workers in high-altitude areas.

    Science.gov (United States)

    Li, Yongling; Liu, Yingshu

    2014-01-01

    Workers coming from lowland regions are at risk of developing acute mountain sickness (AMS) when working in low oxygen high-altitude areas. The aim of this study was to improve the conditions that lead to hypoxia and ensure the safety of the high-altitude workers. We analyzed the influence of low atmospheric pressure on the oxygen enrichment process in high-altitude areas using an engineering method called low-pressure swing adsorption (LPSA). Fourteen male subjects were screened and divided into three groups by type of oxygen supply system used: (1) oxygen cylinder group; (2) LPSA oxygen dispersal group; and (3) control group. These tests included arterial oxygen saturation (SaO2), pulse rate (PR), breaths per minute (BPM), and blood pressure (BP). The results showed that after supplying oxygen using the LPSA method at the tunnel face, the SaO2 of workers increased; the incidence of acute mountain sickness, PR, and BPM significantly decreased. The LPSA life support system was found to be a simple, convenient, efficient, reliable, and applicable approach to ensure proper working conditions at construction sites in high-altitude areas.

  9. Response to Comments on “High Altitude Pulmonary Edema in an Experienced Mountaineer. Possible Genetic Predisposition”

    Directory of Open Access Journals (Sweden)

    Whitlow, K. Scott

    2015-10-01

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

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

    Science.gov (United States)

    Pandey, Priyanka; Mohammad, Ghulam; Singh, Yogendra; Qadar Pasha, MA

    2015-01-01

    Objective To date, a major class of kinases, serine–threonine kinase, has been scantly investigated in stress-induced rare, fatal (if not treated early), and morbid disorder, high altitude pulmonary edema (HAPE). This study examined three major serine–threonine kinases, ROCK2, MYLK, and JNK1, along with six other genes, tyrosine hydroxylase, G-protein subunits GNA11 and GNB3, and alpha1 adrenergic receptor isoforms 1A, 1B, and 1D as candidate gene markers of HAPE and adaptation. Methods For this, 57 variants across these nine genes were genotyped in HAPE patients (n=225), HAPE controls (n=210), and highlanders (n=259) by Sequenom MS (TOF)-based MassARRAY® platform using iPLEX™ Gold technology. In addition, to study the gene expression, quantitative real-time polymerase chain reaction was performed in human peripheral blood mononuclear cells of the three study groups. Results A significant association was observed for C allele (ROCK2 single-nucleotide polymorphism, rs10929728) with HAPE (P=0.03) and C, T, and A alleles (MYLK single-nucleotide polymorphisms, rs11717814, rs40305, and rs820336) with both HAPE and adaptation (P=0.001, P=0.006, and P=0.02, respectively). ROCK2 88 kb GGGTTGGT haplotype was associated with lower risk of HAPE (P=0.0009). MYLK 7 kb haplotype CTA, composed of variant alleles, was associated with higher risk of HAPE (P=0.0006) and lower association with adaptation (P=1E–06), whereas haplotype GCG, composed of wild-type alleles, was associated with lower risk of HAPE (P=0.001) and higher association with adaptation (P=1E–06). Haplotype–haplotype and gene–gene interactions demonstrated a correlation in working of ROCK2 and MYLK. Conclusion The data suggest the association of ROCK2 with HAPE and MYLK with HAPE and adaptation in Indian population. The outcome has provided new insights into the physiology of HAPE and adaptation. PMID:26586960

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

    Directory of Open Access Journals (Sweden)

    Jing-jing HUANG

    2012-04-01

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

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

    Science.gov (United States)

    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.

  13. Characteristics and drivers of high-altitude ladybird flight: insights from vertical-looking entomological radar.

    Directory of Open Access Journals (Sweden)

    Daniel L Jeffries

    Full Text Available Understanding the characteristics and drivers of dispersal is crucial for predicting population dynamics, particularly in range-shifting species. Studying long-distance dispersal in insects is challenging, but recent advances in entomological radar offer unique insights. We analysed 10 years of radar data collected at Rothamsted Research, U.K., to investigate characteristics (altitude, speed, seasonal and annual trends and drivers (aphid abundance, air temperature, wind speed and rainfall of high-altitude flight of the two most abundant U.K. ladybird species (native Coccinella septempunctata and invasive Harmonia axyridis. These species cannot be distinguished in the radar data since their reflectivity signals overlap, and they were therefore analysed together. However, their signals do not overlap with other, abundant insects so we are confident they constitute the overwhelming majority of the analysed data. The target species were detected up to ∼1100 m above ground level, where displacement speeds of up to ∼60 km/h were recorded, however most ladybirds were found between ∼150 and 500 m, and had a mean displacement of 30 km/h. Average flight time was estimated, using tethered flight experiments, to be 36.5 minutes, but flights of up to two hours were observed. Ladybirds are therefore potentially able to travel 18 km in a "typical" high-altitude flight, but up to 120 km if flying at higher altitudes, indicating a high capacity for long-distance dispersal. There were strong seasonal trends in ladybird abundance, with peaks corresponding to the highest temperatures of mid-summer, and warm air temperature was the key driver of ladybird flight. Climatic warming may therefore increase the potential for long-distance dispersal in these species. Low aphid abundance was a second significant factor, highlighting the important role of aphid population dynamics in ladybird dispersal. This research illustrates the utility of radar for studying high-altitude

  14. High-altitude adaptation of Tibetan chicken from MT-COI and ATP-6 perspective.

    Science.gov (United States)

    Zhao, Xiaoling; Wu, Nan; Zhu, Qing; Gaur, Uma; Gu, Ting; Li, Diyan

    2016-09-01

    The problem of hypoxia adaptation in high altitudes is an unsolved brainteaser in the field of life sciences. As one of the best chicken breeds with adaptability to highland environment, the Tibetan chicken, is genetically different from lowland chicken breeds. In order to gain a better understanding of the mechanism of hypoxic adaptability in high altitude, in the present study, we focused on the MT-COI together with ATP-6 gene to explore the regulatory mechanisms for hypoxia adaptability in Tibet chicken. Here, we sequenced MT-COI of 29 Tibetan chickens and 30 Chinese domestic chickens and ATP-6 gene of 28 Tibetan chickens and 29 Chinese domestic chickens. In MT-COI gene, 9 single nucleotide polymorphisms (SNPs) were detected though none of these was a missense mutation, confirming the fact that MT-COI gene is a largely conservative sequence. In ATP-6 gene, 6 single nucleotide polymorphisms (SNPs) were detected and we found a missense mutation (m.9441G > A) in the ATP-6 gene of Tibetan chicken resulting in an amino acid substitution. Due to the critical role of ATP-6 gene in the proton translocation and energy metabolism, we speculated the possibility of this mutation playing an important role in easier energy conversion and metabolism in Tibetan chickens than Chinese domestic chickens so as to better adapt to the harsh environment of the high-altitude areas. The Median-joining profile also suggested that haplotype Ha2 has the ancestral position to the other haplotypes and has significant relationship with high-altitude adaptation in ATP-6 gene. Therefore, we considered that the polymorphism (m.9441G > A) in the ATP-6 gene may affect the specific functions of ATP-6 enzyme relating to high-altitude adaptation of Tibetan chicken and MT-COI gene is a largely conservative sequence.

  15. The effect of high altitude on the glycolytic activity of erythrocytes in natives of the Andean Altiplano.

    Science.gov (United States)

    Arnaud, J; Gutiérrez, N; Vergnes, H

    1983-01-01

    Glucose consumption by anaerobic glycolysis and the pentose pathway were studied in two Aymara populations living at different altitudes (3 600 m and 450 m). The measurements were made both with and without methylene blue. We observed a Pasteur effect for both pathways which may explain the increase in 2-3 DPG and ATP levels found in blood samples from people living at high altitudes. The results in the presence of methylene blue showed a reduced activity of the methaemoglobin reductase system in the high altitude group which may be partly responsible for their increased levels of methaemoglobin.

  16. Rich diversity and potency of skin antioxidant peptides revealed a novel molecular basis for high-altitude adaptation of amphibians.

    Science.gov (United States)

    Yang, Xinwang; Wang, Ying; Zhang, Yue; Lee, Wen-Hui; Zhang, Yun

    2016-01-27

    Elucidating the mechanisms of high-altitude adaptation is an important research area in modern biology. To date, however, knowledge has been limited to the genetic mechanisms of adaptation to the lower oxygen and temperature levels prevalent at high altitudes, with adaptation to UV radiation largely neglected. Furthermore, few proteomic or peptidomic analyses of these factors have been performed. In this study, the molecular adaptation of high-altitude Odorrana andersonii and cavernicolous O. wuchuanensis to elevated UV radiation was investigated. Compared with O. wuchuanensis, O. andersonii exhibited greater diversity and free radical scavenging potentiality of skin antioxidant peptides to cope with UV radiation. This implied that O. andersonii evolved a much more complicated and powerful skin antioxidant peptide system to survive high-altitude UV levels. Our results provided valuable peptidomic clues for understanding the novel molecular basis for adaptation to high elevation habitats.

  17. Peripheral blood mononuclear cell gene expression in healthy adults rapidly transported to high altitude

    Directory of Open Access Journals (Sweden)

    Herman NM

    2014-12-01

    Full Text Available Nicole M Herman,1 Diane E Grill,2 Paul J Anderson,1 Andrew D Miller,1 Jacob B Johnson,1 Kathy A O’Malley,1 Maile L Ceridon Richert,1 Bruce D Johnson1 1Department of Cardiovascular Diseases, 2Department of Biostatistics, Mayo Clinic Rochester, MN, USA Abstract: Although mechanisms of high altitude illness have been studied extensively, the processes behind the development of these conditions are still unclear. Few genome-wide studies on rapid exposure to high altitude have been performed. Each year, scientists and support workers are transferred by plane from McMurdo Station in Antarctica (sea level to the Amundsen-Scott South Pole Station at 2,835 meters. This uniform and rapid transfer to altitude provides a unique opportunity to study the effects of hypobaric hypoxia on gene expression that may help illustrate the body's adaptations to these conditions. We hypothesized that an extensive number of genes would change with rapid exposure to altitude and further expected that these genes would correspond to inflammatory pathways proposed as a mechanism in development of acute mountain sickness. Peripheral venous blood samples were drawn from 98 healthy subjects at sea level and again on day two at altitude. Microarray analysis was performed on these samples. In total, 1,118 probe sets with significant P-values and fold changes (90% upregulated were identified and entered into MetaCore™ software. Several pathways, including oxidative phosphorylation, cytoskeleton remodeling, and platelet aggregation, were significantly represented by the data set and all were upregulated. Many genes changed expression, and the vast majority of these increased. Increased metabolism in peripheral blood mononuclear cells suggests increased inflammatory activity. Keywords: peripheral blood mononuclear cells, microarray, gene expression, acute mountain sickness

  18. Star formation in a diffuse high-altitude cloud?

    CERN Document Server

    Kerp, J; Roehser, T

    2016-01-01

    A recent discovery of two stellar clusters associated with the diffuse high-latitude cloud HRK 81.4-77.8 has important implications for star formation in the Galactic halo. We derive a plausible distance estimate to HRK 81.4-77.8 primarily from its gaseous properties. We spatially correlate state-of-the-art HI, far-infrared and soft X-ray data to analyze the diffuse gas in the cloud. The absorption of the soft X-ray emission from the Galactic halo by HRK 81.4-77.8 is used to constrain the distance to the cloud. HRK 81.4-77.8 is most likely located at an altitude of about 400 pc within the disk-halo interface of the Milky Way Galaxy. The HI data discloses a disbalance in density and pressure between the warm and cold gaseous phases. Apparently, the cold gas is compressed by the warm medium. This disbalance might trigger the formation of molecular gas high above the Galactic plane on pc to sub-pc scales.

  19. Missing correlation of retinal vessel diameter with high-altitude headache

    Science.gov (United States)

    Willmann, Gabriel; Fischer, M Dominik; Schommer, Kai; Bärtsch, Peter; Gekeler, Florian; Schatz, Andreas

    2014-01-01

    The most common altitude-related symptom, high-altitude headache (HAH), has recently been suggested to originate from restricted cerebral venous drainage in the presence of increased inflow caused by hypoxia. In support of this novel hypothesis, retinal venous distension was shown to correlate with the degree of HAH. We quantified for the first time retinal vessel diameter changes at 4559 m using infrared fundus images obtained from a state of the art Spectralis™ HRA+OCT with a semiautomatic VesselMap 1® software. High-altitude exposure resulted in altered arterial and venous diameter changes at high altitude, however, independent of headache burden. PMID:25356382

  20. O+ heating associated with strong wave activity in the high altitude cusp and mantle

    Directory of Open Access Journals (Sweden)

    G. Stenberg

    2011-05-01

    Full Text Available We use the Cluster spacecraft to study three events with intense waves and energetic oxygen ions (O+ in the high altitude cusp and mantle. The ion energies considered are of the order 1000 eV and higher, observed above an altitude of 8 earth radii together with high wave power at the O+ gyrofrequency. We show that heating by waves can explain the observed high perpendicular energy of O+ ions, using a simple gyroresonance model and 25–45% of the observed wave spectral density at the gyrofrequency. This is in contrast to a recently published study where the wave intensity was too low to explain the observed high altitude ion energies. Long lasting cases (>10 min of high perpendicular-to-parallel temperature ratios are sometimes associated with low wave activity, suggesting that high perpendicular-to-parallel temperature ratio is not a good indicator of local heating. Using multiple spacecraft, we show that the regions of enhanced wave activity are at least one order of magnitude larger than the gyroradius of the heated ions.

  1. Quantification of optic disc edema during exposure to high altitude shows no correlation to acute mountain sickness.

    Directory of Open Access Journals (Sweden)

    Gabriel Willmann

    Full Text Available BACKGROUND: The study aimed to quantify changes of the optic nerve head (ONH during exposure to high altitude and to assess a correlation with acute mountain sickness (AMS. This work is related to the Tuebingen High Altitude Ophthalmology (THAO study. METHODOLOGY/PRINCIPAL FINDINGS: A confocal scanning laser ophthalmoscope (cSLO, Heidelberg Retina Tomograph, HRT3® was used to quantify changes at the ONH in 18 healthy participants before, during and after rapid ascent to high altitude (4559 m. Slitlamp biomicroscopy was used for clinical optic disc evaluation; AMS was assessed with Lake Louise (LL and AMS-cerebral (AMS-c scores; oxygen saturation (SpO₂ and heart rate (HR were monitored. These parameters were used to correlate with changes at the ONH. After the first night spent at high altitude, incidence of AMS was 55% and presence of clinical optic disc edema (ODE 79%. Key stereometric parameters of the HRT3® used to describe ODE (mean retinal nerve fiber layer [RNFL] thickness, RNFL cross sectional area, optic disc rim volume and maximum contour elevation changed significantly at high altitude compared to baseline (p<0.05 and were consistent with clinically described ODE. All changes were reversible in all participants after descent. There was no significant correlation between parameters of ODE and AMS, SpO₂ or HR. CONCLUSIONS/SIGNIFICANCE: Exposure to high altitude leads to reversible ODE in the majority of healthy subjects. However, these changes did not correlate with AMS or basic physiologic parameters such as SpO₂ and HR. For the first time, a quantitative approach has been used to assess these changes during acute, non-acclimatized high altitude exposure. In conclusion, ODE presents a reaction of the body to high altitude exposure unrelated to AMS.

  2. Quantification of Optic Disc Edema during Exposure to High Altitude Shows No Correlation to Acute Mountain Sickness

    Science.gov (United States)

    Willmann, Gabriel; Fischer, M. Dominik; Schatz, Andreas; Schommer, Kai; Messias, Andre; Zrenner, Eberhart; Bartz-Schmidt, Karl U.; Gekeler, Florian

    2011-01-01

    Background The study aimed to quantify changes of the optic nerve head (ONH) during exposure to high altitude and to assess a correlation with acute mountain sickness (AMS). This work is related to the Tuebingen High Altitude Ophthalmology (THAO) study. Methodology/Principal Findings A confocal scanning laser ophthalmoscope (cSLO, Heidelberg Retina Tomograph, HRT3®) was used to quantify changes at the ONH in 18 healthy participants before, during and after rapid ascent to high altitude (4559 m). Slitlamp biomicroscopy was used for clinical optic disc evaluation; AMS was assessed with Lake Louise (LL) and AMS-cerebral (AMS-c) scores; oxygen saturation (SpO2) and heart rate (HR) were monitored. These parameters were used to correlate with changes at the ONH. After the first night spent at high altitude, incidence of AMS was 55% and presence of clinical optic disc edema (ODE) 79%. Key stereometric parameters of the HRT3® used to describe ODE (mean retinal nerve fiber layer [RNFL] thickness, RNFL cross sectional area, optic disc rim volume and maximum contour elevation) changed significantly at high altitude compared to baseline (p<0.05) and were consistent with clinically described ODE. All changes were reversible in all participants after descent. There was no significant correlation between parameters of ODE and AMS, SpO2 or HR. Conclusions/Significance Exposure to high altitude leads to reversible ODE in the majority of healthy subjects. However, these changes did not correlate with AMS or basic physiologic parameters such as SpO2 and HR. For the first time, a quantitative approach has been used to assess these changes during acute, non-acclimatized high altitude exposure. In conclusion, ODE presents a reaction of the body to high altitude exposure unrelated to AMS. PMID:22069483

  3. High altitude environmental monitoring: the SHARE project and CEOP-HE

    Science.gov (United States)

    Tartari, G.

    2009-04-01

    -HE) element of regional focus was developed under the GEWEX CEOP programme to study multi-scale variability in water and energy cycles in high elevation areas, and to help improve observations, modelling and data management. Future plans include expansion of the SHARE network, addition of other key research areas including hydrology, and creation of mechanisms to favour exchange of data amongst high altitude networks. In coordination with other global research and monitoring projects (CliC, etc.), SHARE and CEOP-HE could provide a more organic and well-distributed interdisciplinary network, thus allowing governments and international agencies to better face impacts of climate change effects on energy and water budgets and elaborate appropriate adaptation strategies.

  4. High-altitude gastrointestinal bleeding: An observation in Qinghai-Tibetan railroad construction workers on Mountain Tanggula

    Institute of Scientific and Technical Information of China (English)

    Tian-Yi Wu; Shou-Quan Ding; Jin-Liang Liu; Jian-Hou Jia; Rui-Chen Dai; Dong-Chun Zhu; Bao-Zhu Liang; De-Tang Qi; Yong-Fu Sun

    2007-01-01

    AIM: To investigate the gastrointestinal bleeding (GIB) in people from lowland to high altitude and in workers on Mountain Tanggula and its causes as well as treatment and prophylaxis.METHODS: From 2001 to October 2003, we studied GIB in 13 502 workers constructing the railroad on Mountain Tanggula which is 4905 m above the sea level. The incidence of GIB in workers at different altitudes was recorded. Endoscopy was performed when the workersevacuated to Golmud (2808 m) and Xining (2261 m).The available data on altitude GIB were analyzed.RESULTS: The overall incidence of GIB was 0.49% in 13502 workers. The incidence increased with increasing altitude. The onset of symptoms in most patients was within three weeks after arrival at high altitude. Bleeding manifested as hematemesis, melaena or hematochezia,and might be occult. Endoscopic examination showed that the causes of altitude GIB included hemorrhage gastritis, gastric ulcer, duodenal ulcer, and gastric erosion. Experimental studies suggested that acute gastric mucosal lesion (AGML) could be induced by hypoxic and cold stress, which might be the pathogenesis of altitude GIB. Those who consumed large amount of alcohol, aspirin or dexamethasone were at a higher risk of developing GIB. Persons who previously suffered from peptic ulcer or high-altitude polycythemia were also at risk of developing GIB. Early diagnosis, evacuation, and treatment led to early recovery.CONCLUSION: GIB is a potentially life threatening disease, if it is not treated promptly and effectively. Early diagnosis, treatment and evacuation lead to an early recovery. Death due to altitude GIB can be avoided if early symptoms and signs are recognized.

  5. Reduced oxygen due to high-altitude exposure relates to atrophy in motor-function brain areas.

    Science.gov (United States)

    Di Paola, M; Paola, M D; Bozzali, M; Fadda, L; Musicco, M; Sabatini, U; Caltagirone, C

    2008-10-01

    At high altitudes barometric pressure is reduced and, thus, less oxygen is inhaled. Reduced oxygen concentration in brain tissue can lead to cerebral damage and neurological and cognitive deficits. The present study was designed to explore the effects of high-altitude exposure using a quantitative MRI technique, voxel-based morphometry. We studied nine world-class mountain climbers before (baseline) and after (follow-up) an extremely high-altitude ascent of Everest and K2. We investigated the effects of repeated extremely high-altitude exposures by comparing mountain climbers' scans at baseline with scans of 19 controls. In addition, we measured the effects of a single extremely high-altitude expedition by comparing mountain climbers' scans at baseline and follow-up. A region of reduced white matter density/volume was found in the left pyramidal tract near the primary (BA 4) and supplementary (BA 6) motor cortex when mountain climbers at baseline were compared with controls. Further, when mountain climbers' scans before and after the expedition were compared, a region of reduced grey matter density/volume was found in the left angular gyrus (BA 39). These findings suggest that extremely high-altitude exposures may cause subtle white and grey matter changes that mainly affect brain regions involved in motor activity.

  6. Cerebrovascular responses to hypoxia and hypocapnia in high-altitude dwellers.

    Science.gov (United States)

    Norcliffe, L J; Rivera-Ch, M; Claydon, V E; Moore, J P; Leon-Velarde, F; Appenzeller, O; Hainsworth, R

    2005-07-01

    Cerebral blood flow is known to increase in response to hypoxia and to decrease with hypocapnia. It is not known, however, whether these responses are altered in high-altitude dwellers who are not only chronically hypoxic and hypocapnic, but also polycythaemic. Here we examined cerebral blood flow responses to hypoxia and hypocapnia, separately and together, in Andean high-altitude dwellers, including some with chronic mountain sickness (CMS), which is characterized by excessive polycythaemia. Studies were carried out at high altitude (Cerro de Pasco (CP), Peru; barometric pressure (P(B)) 450 mmHg) and repeated, following relief of the hypoxia, on the day following arrival at sea level (Lima, Peru; P(B) 755 mmHg). We compared these results with those from eight sea-level residents studied at sea level. In nine high-altitude normal subjects (HA) and nine CMS patients, we recorded middle cerebral artery mean blood flow velocity (MCAVm) using transcranial Doppler ultrasonography, and expressed responses as changes from baseline. MCAVm responses to hypoxia were determined by changing end-tidal partial pressure of oxygen (P(ET,O2)) from 100 to 50 mmHg, with end-tidal partial pressure of carbon dioxide clamped. MCAVm responses to hypocapnia were studied by voluntary hyperventilation with (P(ET,O2)) clamped at 100 and 50 mmHg. There were no significant differences between the cerebrovascular responses of the two groups to any of the interventions at either location. In both groups, the MCAVm responses to hypoxia were significantly greater at Lima than at CP (HA, 12.1 +/- 1.3 and 6.1 +/- 1.0%; CMS, 12.5 +/- 0.8 and 5.6 +/- 1.2%; P < 0.01 both groups). The responses at Lima were similar to those in the sea-level subjects (13.6 +/- 2.3%). The responses to normoxic hypocapnia in the altitude subjects were also similar at both locations and greater than those in sea-level residents. During hypoxia, both high-altitude groups showed responses to hypocapnia that were

  7. An automatic parachute release for high altitude scientific balloons

    Science.gov (United States)

    Field, Chris

    NASA's Columbia Scientific Balloon Facility launches high altitude scientific research balloons at many locations around the world. Locations like Antarctica are flat for hundreds of miles and have nothing to snag a parachute consequently causing it to be more important to separate the parachute from the payload than in an area with vegetation and fences. Scientists are now building one of a kind payloads costing millions of dollars, taking five years or more to build, and are requesting multiple flights. In addition to that, the data gathering rate of many science payloads far exceeds the data downlink rate on over-the-horizon flights therefore making a recovery of at least the data hard drives a "minimum success requirement". The older mentality in ballooning; separating the parachute and payload from the balloon and getting it on the ground is more important than separating the parachute after the payload is on the ground has changed. It is now equally as important to separate the parachute from the gondola to prevent damage from dragging. Until now, commands had to be sent to separate the parachute from the gondola at approximately 60K ft, 30K ft, and 10K ft to use the Semi Automatic Parachute Release (SAPR), which is after the sometimes violent parachute opening shock. By using the Gondola controlled Automatic Parachute Release (GAPR) all commanding is done prior to termination, making the parachute release fully autonomous.

  8. 21st Century Lightning Protection for High Altitude Observatories

    Science.gov (United States)

    Kithil, Richard

    2013-05-01

    One of the first recorded lightning insults to an observatory was in January 1890 at the Ben Nevis Observatory in Scotland. In more recent times lightning has caused equipment losses and data destruction at the US Air Force Maui Space Surveillance Complex, the Cerro Tololo observatory and the nearby La Serena scientific and technical office, the VLLA, and the Apache Point Observatory. In August 1997 NOAA's Climate Monitoring and Diagnostic Laboratory at Mauna Loa Observatory was out of commission for a month due to lightning outages to data acquisition computers and connected cabling. The University of Arizona has reported "lightning strikes have taken a heavy toll at all Steward Observatory sites." At Kitt Peak, extensive power down protocols are in place where lightning protection for personnel, electrical systems, associated electronics and data are critical. Designstage lightning protection defenses are to be incorporated at NSO's ATST Hawaii facility. For high altitude observatories lightning protection no longer is as simple as Franklin's 1752 invention of a rod in the air, one in the ground and a connecting conductor. This paper discusses selection of engineered lightning protection subsystems in a carefully planned methodology which is specific to each site.

  9. An extremely high altitude plume seen at Mars morning terminator

    Science.gov (United States)

    Sanchez-Lavega, Agustin; Garcia-Muñoz, Antonio; Garcia-Melendo, Enrique; Perez-Hoyos, Santiago; Gomez-Forrellad, Josep M.; Pellier, Christophe; Delcroix, Marc; Lopez-Valverde, Miguel Angel; Gonzalez-Galindo, Francisco; Jaeschke, Wayne; Parker, Donald C.; Phillips, James H.; Peach, Damian

    2014-11-01

    We report the occurrence in March and April 2012 of two bright very high altitude plumes at the Martian terminator at 250 km or more above the surface, thus well into the ionosphere and bordering on the exosphere. They were located at about 195 deg West longitude and -45 deg latitude (at Terra Cimmeria) and lasted for about 10 days. The features showed day-to-day variability, and were seen at the morning terminator but not at the evening limb, which indicates rapid evolution in less than 10 hours and a cyclic behavior. Photometric measurements are used to explore two possible scenarios to explain their nature. If the phenomenon is due to suspended particles (dust, CO2 or H2O ice clouds) reflecting solar radiation, the mean size is about 0.1 microns with a nadir optical depth > 0.06. Alternatively, the plume could be auroral emission above a region with a strong magnetic anomaly and where aurora has previously been detected. Importantly, both explanations defy our current understanding of the Mars upper atmosphere.AcknowledgementsThis work was supported by the Spanish MINECO projects AYA2012-36666 with FEDER support, CONSOLIDER program ASTROMOL CSD2009-00038 and AYA2011-30613-CO2-1. Grupos Gobierno Vasco IT765-13 and UPV/EHU UFI11/55.

  10. The prevalence and severity of dental fluorosis in the high and low altitude parts of Central Plateau, Nigeria.

    Science.gov (United States)

    Akosu, T J; Zoakah, A I; Chirdan, O A

    2009-09-01

    To compare the prevalence and severity of dental fluorosis in the high and low altitude parts of the Central Senatorial District of Plateau State. The study was cross-sectional and descriptive. The community based study was carried out in Central Plateau Nigeria, in 2005. The study subjects were 12-15 year old life long residents selected using the multistage sampling technique. One Local Government Area each was randomly selected from the high and low altitude parts of the district and from each selected Local Government Area two health districts were randomly selected with probability proportional to size. From each of the selected health Districts two major settlements were selected again with probability proportional to size. 12-15 year old life long residents of the selected settlements were studied. Each respondent completed an interviewer administered questionnaire after which he/she was clinically examined to ascertain his/her fluorosis status. Samples of water were collected from water sources consumed by the respondents in each settlement. The main outcome measures were presence and severity of dental fluorosis as measured by the Thylstrup and Fejerskov index. (TF score). One thousand one hundred children were studied, 554 (50.4%) from the high altitude part of the district and 546 (49.6%) from the low altitude part. Fluorosis prevalence was 12.9% in the district, but significantly higher (22.2%) in the high altitude areas compared to the low altitude ones (3.5%). The severest form of fluorosis in the district was TF 6 for tooth 14 and TF 5 for tooth 11. The prevalence and severity of dental fluorosis is significantly higher in the high altitude parts of the District compared to the low altitude ones. Efforts are needed to further investigate and control the problem.

  11. Propagation and Breaking at High Altitudes of Gravity Waves Excited by Tropospheric Forcing

    Science.gov (United States)

    Prusa, Joseph M.; Smolarkiewicz, Piotr K.; Garcia, Rolando R.

    1996-01-01

    An anelastic approximation is used with a time-variable coordinate transformation to formulate a two-dimensional numerical model that describes the evolution of gravity waves. The model is solved using a semi-Lagrangian method with monotone (nonoscillatory) interpolation of all advected fields. The time-variable transformation is used to generate disturbances at the lower boundary that approximate the effect of a traveling line of thunderstorms (a squall line) or of flow over a broad topographic obstacle. The vertical propagation and breaking of the gravity wave field (under conditions typical of summer solstice) is illustrated for each of these cases. It is shown that the wave field at high altitudes is dominated by a single horizontal wavelength; which is not always related simply to the horizontal dimension of the source. The morphology of wave breaking depends on the horizontal wavelength; for sufficiently short waves, breaking involves roughly one half of the wavelength. In common with other studies, it is found that the breaking waves undergo "self-acceleration," such that the zonal-mean intrinsic frequency remains approximately constant in spite of large changes in the background wind. It is also shown that many of the features obtained in the calculations can be understood in terms of linear wave theory. In particular, linear theory provides insights into the wavelength of the waves that break at high altitudes, the onset and evolution of breaking. the horizontal extent of the breaking region and its position relative to the forcing, and the minimum and maximum altitudes where breaking occurs. Wave breaking ceases at the altitude where the background dissipation rate (which in our model is a proxy for molecular diffusion) becomes greater than the rate of dissipation due to wave breaking, This altitude, in effect, the model turbopause, is shown to depend on a relatively small number of parameters that characterize the waves and the background state.

  12. A strategy for reducing neonatal mortality at high altitude using oxygen conditioning.

    Science.gov (United States)

    West, J B

    2015-11-01

    Neonatal mortality increases with altitude. For example, in Peru the incidence of neonatal mortality in the highlands has been shown to be about double that at lower altitudes. An important factor is the low inspired PO2 of newborn babies. Typically, expectant mothers at high altitude will travel to low altitude to have their babies if possible, but often this is not feasible because of economic factors. The procedure described here raises the oxygen concentration in the air of rooms where neonates are being housed and, in effect, this means that both the mother and baby are at a much lower altitude. Oxygen conditioning is similar to air conditioning except that the oxygen concentration of the air is increased rather than the temperature being reduced. The procedure is now used at high altitude in many hotels, dormitories and telescope facilities, and has been shown to be feasible and effective.

  13. The effect of drought on photosynthetic plasticity in Marrubium vulgare plants growing at low and high altitudes.

    Science.gov (United States)

    Habibi, Ghader; Ajory, Neda

    2015-11-01

    Photosynthesis is a biological process most affected by water deficit. Plants have various photosynthetic mechanisms that are matched to specific climatic zones. We studied the photosynthetic plasticity of C3 plants at water deficit using ecotypes of Marrubium vulgare L. from high (2,200 m) and low (1,100 m) elevation sites in the Mishou-Dagh Mountains of Iran. Under experimental drought, high-altitude plants showed more tolerance to water stress based on most of the parameters studied as compared to the low-altitude plants. Increased tolerance in high-altitude plants was achieved by lower levels of daytime stomatal conductance (g s) and reduced damaging effect on maximal quantum yield of photosystem II (PSII) (F v /F m ) coupled with higher levels of carotenoids and non-photochemical quenching (NPQ). High-altitude plants exhibited higher water use efficiency (WUE) than that in low-altitude plants depending on the presence of thick leaves and the reduced daytime stomatal conductance. Additionally, we have studied the oscillation in H(+) content and diel gas exchange patterns to determine the occurrence of C3 or weak CAM (Crassulacean acid metabolism) in M. vulgare through 15 days drought stress. Under water-stressed conditions, low-altitude plants exhibited stomatal conductance and acid fluctuations characteristic of C3 photosynthesis, though high-altitude plants exhibited more pronounced increases in nocturnal acidity and phosphoenolpyruvate carboxylase (PEPC) activity, suggesting photosynthetic flexibility. These results indicated that the regulation of carotenoids, NPQ, stomatal conductance and diel patterns of CO2 exchange presented the larger differences among studied plants at different altitudes and seem to be the protecting mechanisms controlling the photosynthetic performance of M. vulgare plants under drought conditions.

  14. Out of air: Is going to high altitude safe for your patient?

    Science.gov (United States)

    Mendenhall, Ann M; Forest, Christopher P

    2017-08-01

    As more people travel to high altitudes for recreation or work, more travelers with underlying medical conditions will need advice before traveling or treatment for altitude illness. This article focuses on the two main issues for travelers: whether travel to a high altitude will have a negative effect on their underlying medical condition and whether the medical condition increases the patient's risk of developing altitude illness. Although patients with severe pulmonary or cardiac conditions are most at risk in the hypoxic environment, other conditions such as diabetes and pregnancy warrant attention as well.

  15. High Altitude Aerial Natural Gas Leak Detection System

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-12-31

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

  16. Pruning management of Chardonnay grapevines at high altitude in Brazilian southeast

    OpenAIRE

    2016-01-01

    ABSTRACT The agronomical responses of Chardonnay, a variety indicated for sparkling wine production, is influenced by the vineyard management and the edaphoclimatic conditions of the region. The objective of this study was to evaluate the effects of two pruning types (Royat and double Guyot) on vegetative and reproductive development of Chardonnay vine growing at high altitude in the Brazilian southeastern region. The experiment was carried out in a commercial vineyard located at 1,280 m of a...

  17. Influence of acute exposure to high altitude on basal and postprandial plasma levels of gastroenteropancreatic peptides.

    Directory of Open Access Journals (Sweden)

    Rudolf L Riepl

    Full Text Available Acute mountain sickness (AMS is characterized by headache often accompanied by gastrointestinal complaints that vary from anorexia through nausea to vomiting. The aim of this study was to investigate the influence of high altitude on plasma levels of gastroenteropancreatic (GEP peptides and their association to AMS symptoms. Plasma levels of 6 GEP peptides were measured by radioimmunoassay in 11 subjects at 490 m (Munich, Germany and, after rapid passive ascent to 3454 m (Jungfraujoch, Switzerland, over the course of three days. In a second study (n = 5, the same peptides and ghrelin were measured in subjects who consumed standardized liquid meals at these two elevations. AMS symptoms and oxygen saturation were monitored. In the first study, both fasting (morning 8 a.m. and stimulated (evening 8 p.m. plasma levels of pancreatic polypeptide (PP and cholecystokinin (CCK were significantly lower at high altitude as compared to baseline, whereas gastrin and motilin concentrations were significantly increased. Fasting plasma neurotensin was significantly enhanced whereas stimulated levels were reduced. Both fasting and stimulated plasma motilin levels correlated with gastrointestinal symptom severity (r = 0.294, p = 0.05, and r = 0.41, p = 0.006, respectively. Mean O(2-saturation dropped from 96% to 88% at high altitude. In the second study, meal-stimulated integrated (= area under curve plasma CCK, PP, and neurotensin values were significantly suppressed at high altitude, whereas integrated levels of gastrin were increased and integrated VIP and ghrelin levels were unchanged. In summary, our data show that acute exposure to a hypobaric hypoxic environment causes significant changes in fasting and stimulated plasma levels of GEP peptides over consecutive days and after a standardized meal. The changes of peptide levels were not uniform. Based on the inhibition of PP and neurotensin release a reduction of the cholinergic tone can be postulated.

  18. Prevalence of Chronic Mountain Sickness in high altitude districts of Himachal Pradesh

    Directory of Open Access Journals (Sweden)

    Inderjeet Singh Sahota

    2013-01-01

    Full Text Available Introduction: Chronic Mountain Sickness (CMS is a maladaptation condition that can affect people who reside permanently at high altitude (HA. It is characterized by polycythemia, hypoxemia and dyspnea and can be fatal. Over 140 million people live permanently at HA around the world. Unfortunately, research into CMS is lacking and accurate data on the prevalence of this condition do not exist for many regions around the world. In this study, we sought to examine prevalence rates of CMS in the Indian Himalayas, focusing on the Northern State of Himachal Pradesh. Materials and Methods: We surveyed 83 individuals (69 males in eight towns across the HA districts of Sirmaur, Kinnaur and Lahaul and Spiti in Himachal Pradesh, India. Altitudes ranged from 2350 to 4150 m. We used an adapted Qinghai CMS scoring system to diagnose CMS. Information related to subject demographics, medical history, socioeconomic status, and geography were collected to identify risk factors for CMS. Physiologic recordings of oxygen saturation (SpO 2 and pulse rate were made through pulse oximetry. Results: Overall CMS prevalence was 6.17% and mean altitude was 3281 m. At altitudes above 3000 m CMS prevalence rose to 13.73%. All cases of CMS were mild and there was a significant positive correlation between CMS scores and altitude (R = 0.784, P = 0.0213. Mean SpO 2 was 90.7 ± 0.4% and mean pulse rate was 80.3 ± 1.3 bpm. SpO 2 significantly correlated with altitude (R = −0.929, P < 0.001. In our study, age, gender, and tobacco use were not independent risk factors for CMS. Individuals with CMS lived at higher altitudes than their non-CMS counterparts (3736.00 ± 113.30 m vs. 3279.80 ± 69.50 m, respectively; P = 0.017. Conclusion: CMS prevalence in HA towns of the Indian Himalayas of Himachal Pradesh is 6.17% and 13.73% for towns above 3000 m. Further research is required to determine the prevalence of CMS in other regions of the world and to determine risk factors

  19. Changes in body fluid compartments on re-induction to high altitude and effect of diuretics

    Science.gov (United States)

    Singh, M. V.; Rawal, S. B.; Tyagi, A. K.; Bhagat, Maj J. K.; Parshad, R.; Divekar, H. M.

    1988-03-01

    Studies were carried out in 29 healthy young adults in the Indian Army stationed in the plains and posted at an elevation of 3500 m for more than 6 months. After exposure to a low elevation in Delhi (260 m) for 3 weeks they were reinduced to a height of 3500 m. The subjects were divided into three groups, each of which was treated with either placebo or acetazolamide or spironolactone. The drug treatment was started immediately after their landing at high altitude and continued for 2 days only. Total body water, extracellular fluid, intracellular fluid, plasma volume, blood pH, PaO2, PaCO2 and blood viscosity were determined on exposure at Delhi and on re-induction to high altitude. Plasma volume was increased after the descent from high altitude and remained high for up to 21 day's study. This increased plasma volume may have some significance in the pathogenesis of pulmonary oedema. Total body water and intracellular fluid content were increased at 260 m elevation, while extracellular fluid decreased. On re-induction there was a decrease in total body water with no change in the extracellular fluid content.

  20. Lidar observations of high-altitude aerosol layers (cirrus clouds)

    Science.gov (United States)

    Deleva, Atanaska D.; Grigorov, Ivan V.

    2013-03-01

    Aerosols, clouds and aerosol-cloud interactions are recognized as the key factors influencing the climate. Clouds are the primary modulators of the Earth's radiative budget. This paper focuses on the detection of high-altitude aerosol layers in the troposphere over mid-latitude lidar station in Sofia, Bulgaria. They are situated in the height-region 6 km÷16 km, with thickness in the range 0.2 km÷5 km and have varying optical characteristics. On the basis of the general utilized classification of the Cirrus clouds, high values of the calculated atmospheric backscatter coefficient and Angströmexponent estimation results we conclude that the registered strongly scattered aerosol layers are Cirrus clouds. Lidar measurements are performed with an aerosol lidar, equipped with Nd:YAG laser at wavelengths 532 nm and 1064 nm. Mainly, lidar data are presented in terms of vertical atmospheric backscatter coefficient profiles. We also include 2Dcolormap in height-time coordinates build on the basis of so called range corrected signals. It shows in general changes of the aerosol stratification over the lidar station during the measurement period. We employed HYSPLIT backward trajectories and DREAM forecasts to analyze the lidar profile outlines and characterize the events during which Cirrus cloud samples were observed. So was remarked that most of the results were obtained during Saharan dust long-way transport over the city of Sofia. Reported experimental examples are extracted from regular lidar investigations of the atmosphere within the frame of European project EARLINET.

  1. Fasciola hepatica and lymnaeid snails occurring at very high altitude in South America.

    Science.gov (United States)

    Mas-Coma, S; Funatsu, I R; Bargues, M D

    2001-01-01

    Fascioliasis due to the digenean species Fasciola hepatica has recently proved to be an important public health problem, with human cases reported in countries of the five continents, including severe symptoms and pathology, with singular epidemiological characteristics, and presenting human endemic areas ranging from hypo- to hyperendemic. One of the singular epidemiological characteristics of human fascioliasis is the link of the hyperendemic areas to very high altitude regions, at least in South America. The Northern Bolivian Altiplano, located at very high altitude (3800-4100 m), presents the highest prevalences and intensities of human fascioliasis known. Sequences of the internal transcribed spacers ITS-1 and ITS-2 of the nuclear ribosomal DNA of Altiplanic Fasciola hepatica and the intermediate snail host Lymnaea truncatula suggest that both were recently introduced from Europe. Studies were undertaken to understand how the liver fluke and its lymnaeid snail host adapted to the extreme environmental conditions of the high altitude and succeeded in giving rise to high infection rates. In experimental infections of Altiplanic lymnaeids carried out with liver fluke isolates from Altiplanic sheep and cattle, the following aspects were studied: miracidium development inside the egg, infectivity of miracidia, prepatent period, shedding period, chronobiology of cercarial emergence, number of cercariae shed by individual snails, survival of molluscs at the beginning of the shedding process, survival of infected snails after the end of the shedding period and longevity of shedding and non-shedding snails. When comparing the development characteristics of European F. hepatica and L. truncatula, a longer cercarial shedding period and a higher cercarial production were observed, both aspects related to a greater survival capacity of the infected lymnaeid snails from the Altiplano. These differences would appear to favour transmission and may be interpreted as strategies

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

    Science.gov (United States)

    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.

  3. The physiology of extremes: Ancel Keys and the International High Altitude Expedition of 1935.

    Science.gov (United States)

    Tracy, Sarah W

    2012-01-01

    This article examines the International High Altitude Expedition of 1935 and its significance in the life and science of Ancel Keys. Both the expedition and Keys's story afford excellent opportunities to explore the growing reach of interwar physiology into extreme climates-whether built or natural. As IHAE scientists assessed human performance and adaptation to hypoxia, low barometric pressure, and cold, they not only illuminated the physiological and psychological processes of high altitude acclimatization, but they also drew borderlines between the normal and the pathological, paved the way for the neocolonial exploitation of natural and human resources in Latin America, and pioneered field methods in physiology that were adapted and adopted by the Allied Forces during the Second World War. This case study in the physiology of place reveals the power and persistence of environmental determinism within biomedicine well into the twentieth century.

  4. First light at the HAWC high altitude TeV gamma ray detector in Mexico

    Science.gov (United States)

    Fiorino, Daniel

    2012-03-01

    The High Altitude Water Cherenkov (HAWC) Observatory -- currently under construction at 4100m altitude at Pico de Orizaba in Mexico -- is a high duty cycle, large field of view detector for gamma rays at TeV energies. The HAWC Observatory will locate and provide spectra for extended and point sources of TeV gamma rays, probe the cosmic ray anisotropy, search for gamma ray bursts, and set limits on extragalactic background light. Data taking at our smaller test array (VAMOS) is currently under way. I will present results of a first study of several months of VAMOS data, including a first skymap, performance tests, and a search for the shadow of the moon in cosmic rays.

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

    Science.gov (United States)

    Denney, A.

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

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

    Directory of Open Access Journals (Sweden)

    Stacie L. Wing-Gaia

    2014-02-01

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

  7. Agroforestry systems, nutrients in litter and microbial activity in soils cultivated with coffee at high altitude

    Directory of Open Access Journals (Sweden)

    Krystal de Alcantara Notaro

    2014-04-01

    Full Text Available Agroforestry systems are an alternative option for sustainable production management. These systems contain trees that absorb nutrients from deeper layers of the soil and leaf litter that help improve the soil quality of the rough terrain in high altitude areas, which are areas extremely susceptible to environmental degradation. The aim of this study was to characterize the stock and nutrients in litter, soil activity and the population of microorganisms in coffee (Coffea arabica L. plantations under high altitude agroforestry systems in the semi-arid region of the state of Pernambuco, Brazil. Samples were collected from the surface litter together with soil samples taken at two depths (0-10 and 10-20 cm from areas each subject to one of the following four treatments: agroforestry system (AS, native forest (NF, biodynamic system (BS and coffee control (CT.The coffee plantation had been abandoned for nearly 15 years and, although there had been no management or harvesting, still contained productive coffee plants. The accumulation of litter and mean nutrient content of the litter, the soil nutrient content, microbial biomass carbon, total carbon, total nitrogen, C/N ratio, basal respiration, microbial quotient, metabolic quotient and microbial populations (total bacteria, fluorescent bacteria group, total fungi and Trichoderma spp. were all analyzed. The systems thatwere exposed to human intervention (A and BS differed in their chemical attributes and contained higher levels of nutrients when compared to NF and CT. BS for coffee production at high altitude can be used as a sustainable alternative in the high altitude zones of the semi-arid region in Brazil, which is an area that is highly susceptible to environmental degradation.

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

    NARCIS (Netherlands)

    DEMEER, K; HEYMANS, HSA; ZIJLSTRA, WG

    1995-01-01

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

  9. Acetazolamide improves cerebral oxygenation during exercise at high altitude

    NARCIS (Netherlands)

    Vuyk, J.; Bos, J. van den; Terhell, K.; Bos, R. de; Vletter, A.; Valk, P.; Beuzekom, M. van; Kleef, J. van; Dahan, A.

    2006-01-01

    Acute mountain sickness is thought to be triggered by cerebral hypoxemia and be prevented by acetazolamide (Actz). The effect of Actz on cerebral oxygenation at altitude remains unknown. In 16 members of the 2005 Dutch Cho Oyu (8201 m, Tibet) expedition, the influence of Actz and exercise (750 mg PO

  10. Outdoor Activity and High Altitude Exposure During Pregnancy: A Survey of 459 Pregnancies.

    Science.gov (United States)

    Keyes, Linda E; Hackett, Peter H; Luks, Andrew M

    2016-06-01

    To evaluate whether women engage in outdoor activities and high altitude travel during pregnancy; the health care advice received regarding high altitude during pregnancy; and the association between high altitude exposure and self-reported pregnancy complications. An online survey of women with at least 1 pregnancy distributed on websites and e-mail lists targeting mothers and/or mountain activities. Outcome measures were outdoor activities during pregnancy, high altitude (>2440 m) exposure during pregnancy, and pregnancy and perinatal complications. Hiking, running, and swimming were the most common activities performed during pregnancy. Women traveled to high altitude in over half of the pregnancies (244/459), and most did not receive counseling regarding altitude (355, 77%), although a small proportion (14, 3%) were told not to go above 2440 m. Rates of miscarriage and most other complications were similar between pregnancies with and without travel above 2440 m. Pregnancies with high altitude exposure were more likely to have preterm labor (odds ratio [OR] 2.3; 95% CI 0.97-5.4; P = .05). Babies born to women who went to high altitude during pregnancy were more likely to need oxygen at birth (OR 2.34; 95% CI 1.04-5.26; P < .05) but had similar rates of neonatal intensive care unit admission (P = not significant). Our results suggest pregnant women who are active in outdoor sports and travel to high altitude have a low rate of complications. Given the limitations of our data, further research is necessary on the risks associated with high altitude travel and physical activity and how these apply to the general population. Copyright © 2016 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  11. A novel candidate region for genetic adaptation to high altitude in Andean populations.

    Directory of Open Access Journals (Sweden)

    Guido Valverde

    Full Text Available Humans living at high altitude (≥ 2,500 meters above sea level have acquired unique abilities to survive the associated extreme environmental conditions, including hypoxia, cold temperature, limited food availability and high levels of free radicals and oxidants. Long-term inhabitants of the most elevated regions of the world have undergone extensive physiological and/or genetic changes, particularly in the regulation of respiration and circulation, when compared to lowland populations. Genome scans have identified candidate genes involved in altitude adaption in the Tibetan Plateau and the Ethiopian highlands, in contrast to populations from the Andes, which have not been as intensively investigated. In the present study, we focused on three indigenous populations from Bolivia: two groups of Andean natives, Aymara and Quechua, and the low-altitude control group of Guarani from the Gran Chaco lowlands. Using pooled samples, we identified a number of SNPs exhibiting large allele frequency differences over 900,000 genotyped SNPs. A region in chromosome 10 (within the cytogenetic bands q22.3 and q23.1 was significantly differentiated between highland and lowland groups. We resequenced ~1.5 Mb surrounding the candidate region and identified strong signals of positive selection in the highland populations. A composite of multiple signals like test localized the signal to FAM213A and a related enhancer; the product of this gene acts as an antioxidant to lower oxidative stress and may help to maintain bone mass. The results suggest that positive selection on the enhancer might increase the expression of this antioxidant, and thereby prevent oxidative damage. In addition, the most significant signal in a relative extended haplotype homozygosity analysis was localized to the SFTPD gene, which encodes a surfactant pulmonary-associated protein involved in normal respiration and innate host defense. Our study thus identifies two novel candidate genes and

  12. Freestanding Flag-Type Triboelectric Nanogenerator for Harvesting High-Altitude Wind Energy from Arbitrary Directions.

    Science.gov (United States)

    Zhao, Zhenfu; Pu, Xiong; Du, Chunhua; Li, Linxuan; Jiang, Chunyan; Hu, Weiguo; Wang, Zhong Lin

    2016-02-23

    Wind energy at a high altitude is far more stable and stronger than that near the ground, but it is out of reach of the wind turbine. Herein, we develop an innovative freestanding woven triboelectric nanogenerator flag (WTENG-flag) that can harvest high-altitude wind energy from arbitrary directions. The wind-driven fluttering of the woven unit leads to the current generation by a coupled effect of contact electrification and electrostatic induction. Systematic study is conducted to optimize the structure/material parameters of the WTENG-flag to improve the power output. This 2D WTENG-flag can also be stacked in parallel connections in many layers for a linearly increased output. Finally, a self-powered high-altitude platform with temperature/humidity sensing/telecommunicating capability is demonstrated with the WTENG-flag as a power source. Due to the light weight, low cost, and easy scale-up, this WTENG-flag has great potential for applications in weather/environmental sensing/monitoring systems.

  13. Comparing high altitude treatment with current best care in Dutch children with moderate to severe atopic dermatitis (and asthma): study protocol for a pragmatic randomized controlled trial (DAVOS trial).

    Science.gov (United States)

    Fieten, Karin B; Zijlstra, Wieneke T; van Os-Medendorp, Harmieke; Meijer, Yolanda; Venema, Monica Uniken; Rijssenbeek-Nouwens, Lous; l'Hoir, Monique P; Bruijnzeel-Koomen, Carla A; Pasmans, Suzanne G M A

    2014-03-26

    About 10 to 20% of children in West European countries have atopic dermatitis (AD), often as part of the atopic syndrome. The full atopic syndrome also consists of allergic asthma, allergic rhinitis and food allergy. Treatment approaches for atopic dermatitis and asthma include intermittent anti-inflammatory therapy with corticosteroids, health education and self-management training. However, symptoms persist in a subgroup of patients. Several observational studies have shown significant improvement in clinical symptoms in children and adults with atopic dermatitis or asthma after treatment at high altitude, but evidence on the efficacy when compared to treatment at sea level is still lacking. This study is a pragmatic randomized controlled trial for children with moderate to severe AD within the atopic syndrome. Patients are eligible for enrolment in the study if they are: diagnosed with moderate to severe AD within the atopic syndrome, aged between 8 and 18 years, fluent in the Dutch language, have internet access at home, able to use the digital patient system Digital Eczema Center Utrecht (DECU), willing and able to stay in Davos for a six week treatment period. All data are collected at the Wilhelmina Children's Hospital and DECU. Patients are randomized over two groups. The first group receives multidisciplinary inpatient treatment during six weeks at the Dutch Asthma Center in Davos, Switzerland. The second group receives multidisciplinary treatment during six weeks at the outpatient clinic of the Wilhelmina Children's Hospital, Utrecht, the Netherlands. The trial is not conducted as a blind trial. The trial is designed with three components: psychosocial, clinical and translational. Primary outcomes are coping with itch, quality of life and disease activity. Secondary outcomes include asthma control, medication use, parental quality of life, social and emotional wellbeing of the child and translational parameters. The results of this trial will provide

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

    NARCIS (Netherlands)

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

    2012-01-01

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

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  16. Characteristics of flame spread over the surface of charring solid combustibles at high altitude

    Institute of Scientific and Technical Information of China (English)

    LI Jie; JI Jie; ZHANG Ying; SUN JinHua

    2009-01-01

    To explore the characteristics of flame spread over the surface of charring solid combustibles at high altitude, the whitewood with uniform texture was chosen to conduct a series of experiments in Lhasa and Hefei, with altitude of 3658 m and 50 m respectively. Several parameters, including the flame height, flame spread rate, flame temperature, surface temperature, were measured on samples with different width and inclinations. A quantitative analysis of flame spread characteristics over sample surface at high altitude was performed. Results showed that, in the environment of lower pressure and oxygen concentration at high altitude, the flame height and flame spread rate over sample surface decreased, but the flame temperature increased slightly. However, with increasing of sample width, the relative difference between the flame spread rates at different altitudes decreased.

  17. Circulatory adaptation to long-term high altitude exposure in Aymaras and Caucasians.

    Science.gov (United States)

    Stuber, Thomas; Scherrer, Urs

    2010-01-01

    About 30 million people live above 2500 m in the Andean Mountains of South America. Among them are 5.5 million Aymaras, an ethnic group with its own language, living on the altiplano of Bolivia, Peru, and northern Chile at altitudes of up to 4400 m. In this high altitude region traces of human population go back for more than 2000 years with constant evolutionary pressure on its residents for genetic adaptation to high altitude. Aymaras as the assumed direct descendents of the ancient cultures living in this region were the focus of much research interest during the last decades and several distinctive adaptation patterns to life at high altitude have been described in this ethnic group. The aim of this article was to review the physiology and pathophysiology of circulatory adaptation and maladaptation to longtime altitude exposure in Aymaras and Caucasians.

  18. Reaching High Altitudes on Mars with an Inflatable Hypersonic Drag Balloon (Ballute)

    CERN Document Server

    Griebel, Hannes

    2010-01-01

    The concept of probing the atmosphere of planet Mars by means of a hypersonic drag balloon, a device known as a “ballute”, is a novel approach to planetary science. In this concept, the probe deploys an inflatable drag body out in space and may then enter the atmosphere either once or several times until it slowly descends towards the ground, taking continuous atmospheric and other readings across a large altitude and ground range. Hannes Griebel discusses the theory behind such a mission along with experience gained during its practical implementation, such as mission design, manufacturing, packing and deployment techniques as well as ground and flight tests. The author also studies other ballute applications, specifically emergency low Earth orbit recovery and delivering payloads to high altitude landing sites on Mars.

  19. Food Abundance Is the Main Determinant of High-Altitude Range Use in Snub-Nosed Monkeys

    Directory of Open Access Journals (Sweden)

    Cyril C. Grueter

    2012-01-01

    Full Text Available High-altitude dwelling primates have to optimize navigating a space that contains both a vertical and horizontal component. Black-and-white or Yunnan snub-nosed monkeys (Rhinopithecus bieti are extreme by primate standards in inhabiting relatively cold subalpine temperate forests at very high altitudes where large seasonal variation in climate and food availability is expected to profoundly modulate their ranging strategies so as to ensure a positive energy balance. A “semi-nomadic” group of R. bieti was followed for 20 months in the montane Samage Forest, Baimaxueshan Nature Reserve, Yunnan, PRC, which consisted of evergreen conifers, oaks, and deciduous broadleaf trees. The aim of this study was to disentangle the effects of climate and phenology on patterns of altitudinal range use. Altitude used by the group ranged from a maximum of 3550 m in July 2007 to a minimum of 3060 m in April 2006. The proportional use of lichen, the monkeys’ staple fallback food, in the diet explained more variation in monthly use of altitudes than climatic factors and availability of flush and fruit. The abundance of lichens at high altitudes, the lack of alternative foods in winter, and the need to satisfy the monkey's basal energetic requirements explain the effect of lichenivory on use of altitudes.

  20. Aliskiren Trial in Type 2 Diabetes Using Cardio-Renal Endpoints (ALTITUDE): rationale and study design

    DEFF Research Database (Denmark)

    Parving, Hans-Henrik; Brenner, Barry M; McMurray, John J V;

    2009-01-01

    , resuscitated death, myocardial infarction, stroke, unplanned hospitalization for heart failure, onset of end-stage renal disease or doubling of baseline serum creatinine concentration. Secondary endpoints include a composite CV endpoint and a composite renal endpoint. CONCLUSION: ALTITUDE will determine...... the residual renal and cardiovascular risk still remains high. Aliskiren a novel oral direct renin inhibitor that unlike ACEi and ARBs, lowers plasma renin activity, angiotensin I and angiotensin II levels, may thereby provide greater benefit compared to ACEi or ARB alone. METHODS: The primary objective...... of the ALTITUDE trial is to determine whether aliskiren 300 mg once daily, reduces cardiovascular and renal morbidity and mortality compared with placebo when added to conventional treatment (including ACEi or ARB). ALTITUDE is an international, randomized, double-blind, placebo-controlled, parallel-group study...

  1. Exercise at simulated high altitude facilitates the increase in capillarity in skeletal muscle of rats

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    AIM: To study the changes in capillarity of skeletal muscle during acclimation to high altitude, and explore the effects of a certain extent physical activity under hypoxia on capillary formation and the role of vascular endothelial growth factor (VEGF) in this process. METHODS: 48 Wistar rats were divided into 3 groups: Ⅰ normoxic control; Ⅱ hypoxia and Ⅲ hypoxia+exercise. Rats of Ⅱ and Ⅲ groups were subjected to hypobaric hypoxia for 5 weeks (23 h/d). They were first brought to simulated 4 000 m altitude, where rats of the Ⅲgroup were forced to swim for 1 h/d (6 d/week). Then the animals were ascent to 5 000 m. Biomicrosphere method was used to determine blood flow of skeletal muscle. The mean fiber cross-sectional area (FCSA), capillary density (CD) and capillary/fiber ratio (C/F) of red portion of the lateral head of the gastrocneminus were assayed by myofibrillar ATPase histochemistry. VEGF and its receptor KDR were assayed with immunohistochemistry method.RESULTS: By comparison with the normoxic control, 5-week hypoxic exposure resulted in a decrease in cross-sectional area of skeletal muscle fiber and an increase in CD, but the C/F remained unchanged. The blood supply to the gastrocnemius was not changed. After 5-week-exercise at high altitude, the muscle fibers did not undergo atrophy. CD, C/F, and the blood flow at rest increased significantly. VEGF protein was found primarily in the matrix between muscle fibers; KDR were shown mainly in endothelial cells of capillary. VEGF was more strongly stained in the skeletal muscle of hypoxia-exercise rats.CONCLUSION: Hypoxia itself can not induce neovascularization. While exercise during hypoxic exposure can lead to capillary formation. VEGF and KDR may play roles in it. New capillary formation benefits the blood supply, oxygen delivery and working performance at high altitude.

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

    Science.gov (United States)

    1996-10-01

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

  3. Emission characteristics of a heavy-duty diesel engine at simulated high altitudes.

    Science.gov (United States)

    He, Chao; Ge, Yunshan; Ma, Chaochen; Tan, Jianwei; Liu, Zhihua; Wang, Chu; Yu, Linxiao; Ding, Yan

    2011-08-01

    In order to evaluate the effects of altitude on the pollutant emissions of a diesel engine, an experimental research was carried out using an engine test bench with an altitude simulation system. The emissions of HC, CO, NOx, smoke, and particle number of a heavy-duty diesel engine were measured under steady state operating conditions at sea level and simulated altitudes of 1000 and 2000 m. The experimental results indicate that the high altitude increases the emissions of HC, CO and smoke of the diesel engine, the average increasing rates of which are 30%, 35% and 34% with addition of altitude of 1000 m, respectively. The effect of high altitudes on the NOx emission varies with the engine types and working conditions. At 1000 m the particles number emissions are 1.6 to 4.2 times the levels at the low altitude. The pattern of the particle size distributions at 1000 m is similar with that at sea-level, which is the mono-modal lognormal distribution with geometric mean diameter around 0.1 μm. However, the peak number concentrations of particles are bigger and the exhausted particles are smaller at the high altitude.

  4. High altitude aerodynamic platform concept evaluation and prototype engine testing

    Science.gov (United States)

    Akkerman, J. W.

    1984-01-01

    A design concept has been developed for maintaining a 150-pound payload at 60,000 feet altitude for about 50 hours. A 600-pound liftoff weight aerodynamic vehicle is used which operates at sufficient speeds to withstand prevailing winds. It is powered by a turbocharged four-stoke cycle gasoline fueled engine. Endurance time of 100 hours or more appears to be feasible with hydrogen fuel and a lighter payload. A prototype engine has been tested to 40,000 feet simulated altitude. Mismatch of the engine and the turbocharger system flow and problems with fuel/air mixture ratio control characteristics prohibited operation beyond 40,000 feet. But there seems to be no reason why the concept cannot be developed to function as analytically predicted.

  5. Association between Serum Interleukin-17A Level and High-Altitude Deacclimatization Syndrome

    Directory of Open Access Journals (Sweden)

    Binfeng He

    2016-01-01

    Full Text Available High-altitude deacclimatization syndrome (HADAS is emerging as a severe public health issue that threatens the quality of life of individuals who return to lower altitude from high altitude. In this study, we measured serum levels of SOD, MDA, IL-17A, IL-10, TNF-α, and HADAS score in HADAS subjects at baseline and 50th and 100th days and to evaluate the relationship between interleukins, including IL-17A, and HADAS. Our data showed that and the serum IL-17A levels and HADAS score decreased over time in the HADAS group, and serum IL-17A levels were significantly higher in the HADAS group at baseline and 50th day compared with controls (p<0.05. Furthermore, baseline serum levels of MDA and TNF-α were significantly higher, while SOD and IL-10 levels were lower in HADAS subjects compared with controls (p<0.05. It is interesting that serum levels of IL-17A were clearly interrelated with HADAS incidence and severity (p<0.05. ROC curve analysis showed that combined serum IL-17A and IL-10 levels were a better predictor of HADAS incidence than serum levels of IL-17A or IL-10 alone. These data suggest that serum levels of IL-17A are a novel predictive index of HADAS.

  6. Protective effect of ginkgolide B on high altitude cerebral edema of rats.

    Science.gov (United States)

    Botao, Yu; Ma, Jie; Xiao, Wenjing; Xiang, Qingyu; Fan, Kaihua; Hou, Jun; Wu, Juan; Jing, Weihua

    2013-03-01

    Ginkgolide B (GB) is one of the ginkgolides isolated from leaves of the Ginkgo biloba tree. The aim of this study was to investigate whether GB has a protective effect on high altitude cerebral edema (HACE) of rats. HACE was induced by hypobaric hypoxia exposure for 24 hours in an animal decompression chamber with the chamber pressure of 267 mmHg to simulate an altitude of 8000 m. Before the exposure, three doses (3, 6, and 12 mg·kg(-1)) of GB were given intraperitoneally (ip) daily for 3 days. Effects of GB on brain water content (BWC), activity of superoxide dismutase (SOD), concentration of glutathione (GSH) and malondialdehyde (MDA), expression of active caspase-3 and poly(ADP-ribose) polymerase (PARP) were measured. In GB pretreatment groups (6 and 12 mg·kg(-1), but not 3 mg·kg(-1)), BWC, the concentration of MDA, the expression of active caspase-3 and PARP were reduced significantly, while the activity of SOD and concentration of GSH were significantly increased. In conclusion, these results indicate that GB has a protective effect on cerebral edema caused by high altitude in rats. The protective effect of GB might be attributed to its antioxidant properties and suppression of the caspase-dependent apoptosis pathway.

  7. SPARCL: a high-altitude tethered balloon-based optical space-to-ground communication system

    Science.gov (United States)

    Badesha, Surjit S.

    2002-12-01

    The Johns Hopkins University Applied Physics Laboratory (JHU/APL) has conducted a feasibility study to determine if a high altitude (20 km) tethered balloon-based space-to-ground optical communication system is a feasible concept. To support this effort, a detailed concept definition was developed and associated issues were identified and analyzed systematically. Of all the adverse atmospheric phenomena, cloud coverage was identified as the most prohibitive obstacle for a space-to-ground optical communication link. However, by placing a receiver on a balloon at a 20 km altitude, the proposed high altitude system avoids virtually all atmospheric effects. A practical notional scenario was developed (i.e. surveillance and/or reconnaissance of a regional conflict) involving end-to-end optical communication architecture to identify system elements, system level requirements, and to quantify realistic data rate requirements. Analysis of the proposed space-to-ground communication elements indicates that while significant development is required, the system is technically feasible and is a very cost effective 24/7solution.

  8. Body mass index and age at menarche in Peruvian children living at high altitude and at sea level.

    Science.gov (United States)

    Gonzales, G F; Villena, A

    1996-04-01

    The present study was designed to determine the relationship between body mass index (BMI) and age at menarche in girls (aged 10-19 years) living in Lima (150 m) and in Cerro de Pasco (4340 m above sea level). The purpose of the study was to determine whether the relationships between BMI and both age at menarche and chronological age differ between girls living at low and at high altitude. The ratio weight/height (the Benn index) was used in the present study as a variant of BMI because the exponent minimizes the relationship with height and maximizes the relationship with weight. From 10 to 16 years of age the Benn index of highlander girls was lower than that for girls at sea level, but at 17-19 years the differences disappeared. A later age at menarche was observed at high altitude than at sea level after controlling for socioeconomic status and for the Benn index. The value of the Benn index at the time of menarche, after controlling for chronological age in the analysis, was significantly higher at high altitude than at sea level. It was also observed that the higher the chronological age, the lower the value of the Benn index at the time of menarche. Using the median ages at menarche in Lima and in Cerro de Pasco, we found that a higher Benn index at the time of menarche is still observed at high altitude compared with girls from sea level. In Lima body weight and height were directly related to age at menarche (p Cerro de Pasco only weight was related to age at menarche (p Cerro de Pasco is an independent effect of altitude. Because the Benn index for menarche was different at sea level and at high altitude, we conclude that regression equations to predict age at menarche must include altitude as an independent variable.

  9. Carbon accumulation in high-altitude peatlands of the Central Andes of Peru

    Science.gov (United States)

    Llanos, Romina; Moreira-Turcq, Patricia; Huaman, Yizet; Espinoza, Raul; Apaestegui, James; Turcq, Bruno; Willems, Bram

    2017-04-01

    Despite covering only 6 - 8% of the world's land surface, peatlands contain around one third of the global organic soil carbon (C) and are an important component of the global C cycle. Most studies of peatland C dynamics have been carried out on boreal and subarctic peatlands, but less is known about peatlands at lower latitudes, yet there are significant peatland C stocks in these regions that may be more vulnerable to future climate change because they are closer to the climatic limit of peatland distribution. In South America, peatlands in high altitudes called "bofedales" represent one of the most important water resources and also provide key environmental services that support both Andean mountain biodiversity and the wellbeing of human populations. Nowdays, the need for conservation and wise use of these ecosystems is increasingly being recognized. So, a useable assessment of peatlands in the global C cycle requires accurate estimates of carbon pools and fluxes. In order to understand the impact of different altitudes on the growth, production and carbon accumulation, several short (about 30 cm) peatlands cores were collected in the headwater of the Cachi river basin, in the Central Andes of Peru. Two Distichia muscoides cushion plant-dominated "bofedales" which elevations exceed 4000 m were studied. The sedimentation rates, based on radiocarbon dating of peat samples from the two sites studied, were very variable. Cores from the bofedal located at 4200 m present an age of approximately 55 years, while the site at the highest altitude site has an age of approximately about 450 years. Our results point out very different rates of sedimentation in the two peatlands that may be related to the climatic changes observed during the recent past, with a direct consequence on the carbon accumulation rates. In the determination of the annual growth, we observed that this one presented smaller values in the first centimeters of the peatland with lower elevation, while

  10. Hydrological processes in glacierized high-altitude basins of the western Himalayas

    Science.gov (United States)

    Jeelani, Ghulam; Shah, Rouf A.; Fryar, Alan E.; Deshpande, Rajendrakumar D.; Mukherjee, Abhijit; Perrin, Jerome

    2017-09-01

    Western Himalaya is a strategically important region, where the water resources are shared by China, India and Pakistan. The economy of the region is largely dependent on the water resources delivered by snow and glacier melt. The presented study used stable isotopes of water to further understand the basin-scale hydro-meteorological, hydrological and recharge processes in three high-altitude mountainous basins of the western Himalayas. The study provided new insights in understanding the dominant factors affecting the isotopic composition of the precipitation, snowpack, glacier melt, streams and springs. It was observed that elevation-dependent post-depositional processes and snowpack evolution resulted in the higher isotopic altitude gradient in snowpacks. The similar temporal trends of isotopic signals in rivers and karst springs reflect the rapid flow transfer due to karstification of the carbonate aquifers. The attenuation of the extreme isotopic input signal in karst springs appears to be due to the mixing of source waters with the underground karst reservoirs. Basin-wise, the input-output response demonstrates the vital role of winter precipitation in maintaining the perennial flow in streams and karst springs in the region. Isotopic data were also used to estimate the mean recharge altitude of the springs.

  11. Barcroft's bold assertion: All dwellers at high altitudes are persons of impaired physical and mental powers.

    Science.gov (United States)

    West, John B

    2016-03-01

    Barcroft's bold assertion that everyone at high altitude has physical and mental impairment compared with sea level was very provocative. It was a result of the expedition that he led to Cerro de Pasco in Peru, altitude 4300 m. Although it is clear that newcomers to high altitude have reduced physical powers, some people believe that this does not apply to permanent residents who have been at high altitude for generations. The best evidence supports Barcroft's contention, although permanent residents often perform better than acclimatized lowlanders. Turning to neuropsychological function, newcomers to high altitude certainly have some impairment, and there is evidence that the same applies to highlanders. However the notion that permanent residents are impaired is anathema to many people. For example the eminent Peruvian physician Carlos Monge took great exception to Barcroft's remark and even attributed it to the fact that Barcroft was suffering from acute mountain sickness when he made it! Monge referred to 'climatic aggression', by which he meant the negative consequences of the inevitable hypoxia of high altitude. Recent technological advances such as oxygen enrichment of room air can overcome this 'aggression'. This might be useful in some settings at high altitude such as a nursery where newborn babies are cared for, and possibly operating rooms where the surgeon's dexterity may be enhanced. Other situations might be dormitories, conference rooms, and perhaps some school rooms. These constitute possible ways by which the effects of Barcroft's assertion might be countered.

  12. Subclinical high altitude pulmonary edema:A clinical observation of 12 cases in Yushu

    Institute of Scientific and Technical Information of China (English)

    Li Shuzhi; Zheng Bihai; Wu Tianyi; Chen Huixing; Zhang Ming

    2013-01-01

    During the Yushu Earthquake on April 14,2010,a high incidence of acute high altitude illness was observed in the mountain rescuers,and 0.73 % of these patients suffered from high altitude pulmonary edema,of which 12 patients developed subclinical pulmonary edema and concomitantly contracted acute mountain sickness.Symptoms and signs were atypically high heart rate with high respiratory rate,striking cyanosis,and significantly low oxygen saturation,whereas no moist rates were heard on auscultation,and Chest X-ray showed peripheral with a patchy distribution of mottled infiltrations in one or both lung fields.We believe that subclinical high altitude pulmonary edema is an earliest stage of pulmonary edema at high altitude.The possible pathogenesis and the diagnosis were discussed.

  13. Glucose intolerance associated with hypoxia in people living at high altitudes in the Tibetan highland

    Science.gov (United States)

    Okumiya, Kiyohito; Sakamoto, Ryota; Ishimoto, Yasuko; Kimura, Yumi; Fukutomi, Eriko; Ishikawa, Motonao; Suwa, Kuniaki; Imai, Hissei; Chen, Wenling; Kato, Emiko; Nakatsuka, Masahiro; Kasahara, Yoriko; Fujisawa, Michiko; Wada, Taizo; Wang, Hongxin; Dai, Qingxiang; Xu, Huining; Qiao, Haisheng; Ge, Ri-Li; Norboo, Tsering; Tsering, Norboo; Kosaka, Yasuyuki; Nose, Mitsuhiro; Yamaguchi, Takayoshi; Tsukihara, Toshihiro; Ando, Kazuo; Inamura, Tetsuya; Takeda, Shinya; Ishine, Masayuki; Otsuka, Kuniaki; Matsubayashi, Kozo

    2016-01-01

    Objectives To clarify the association between glucose intolerance and high altitudes (2900–4800 m) in a hypoxic environment in Tibetan highlanders and to verify the hypothesis that high altitude dwelling increases vulnerability to diabetes mellitus (DM) accelerated by lifestyle change or ageing. Design Cross-sectional epidemiological study on Tibetan highlanders. Participants We enrolled 1258 participants aged 40–87 years. The rural population comprised farmers in Domkhar (altitude 2900–3800 m) and nomads in Haiyan (3000–3100 m), Ryuho (4400 m) and Changthang (4300–4800 m). Urban area participants were from Leh (3300 m) and Jiegu (3700 m). Main outcome measure Participants were classified into six glucose tolerance-based groups: DM, intermediate hyperglycaemia (IHG), normoglycaemia (NG), fasting DM, fasting IHG and fasting NG. Prevalence of glucose intolerance was compared in farmers, nomads and urban dwellers. Effects of dwelling at high altitude or hypoxia on glucose intolerance were analysed with the confounding factors of age, sex, obesity, lipids, haemoglobin, hypertension and lifestyle, using multiple logistic regression. Results The prevalence of DM (fasting DM)/IHG (fasting IHG) was 8.9% (6.5%)/25.1% (12.7%), respectively, in all participants. This prevalence was higher in urban dwellers (9.5% (7.1%)/28.5% (11.7%)) and in farmers (8.5% (6.1%)/28.5% (18.3%)) compared with nomads (8.2% (5.7%)/15.7% (9.7%)) (p=0.0140/0.0001). Dwelling at high altitude was significantly associated with fasting IHG+fasting DM/fasting DM (ORs for >4500 and 3500–4499 m were 3.59/4.36 and 2.07/1.76 vs 3500 m play a major role in the high prevalence of glucose intolerance in highlanders. Tibetan highlanders may be vulnerable to glucose intolerance, with polycythaemia as a sign of poor hypoxic adaptation, accelerated by lifestyle change and ageing. PMID:26908520

  14. High Altitude Pulmonary Edema in an Experienced Mountaineer. Possible Genetic Predisposition

    Directory of Open Access Journals (Sweden)

    Kenneth S. Whitlow,

    2014-11-01

    Full Text Available High altitude pulmonary edema (HAPE is a form of high altitude illness characterized by cough, dyspnea upon exertion progressing to dyspnea at rest and eventual death, seen in patients who ascend over 2,500 meters, particularly if that ascent is rapid. This case describes a patient with no prior history of HAPE and extensive experience hiking above 2,500 meters who developed progressive dyspnea and cough while ascending to 3,200 meters. His risk factors included rapid ascent, high altitude, male sex, and a possible genetic predisposition for HAPE. [West J Emerg Med. 2014;15(7:–0.

  15. High Altitude Pulmonary Edema in an Experienced Mountaineer. Possible Genetic Predisposition

    Science.gov (United States)

    Whitlow, Kenneth S.; Davis, Babette W.

    2014-01-01

    High altitude pulmonary edema (HAPE) is a form of high altitude illness characterized by cough, dyspnea upon exertion progressing to dyspnea at rest and eventual death, seen in patients who ascend over 2,500 meters, particularly if that ascent is rapid. This case describes a patient with no prior history of HAPE and extensive experience hiking above 2,500 meters who developed progressive dyspnea and cough while ascending to 3,200 meters. His risk factors included rapid ascent, high altitude, male sex, and a possible genetic predisposition for HAPE. PMID:25493133

  16. 高海拔地区土石坝技术研究%Study of Key Technology of Earth-Rock Dam in High Altitude Areas

    Institute of Scientific and Technical Information of China (English)

    张宝琼; 林赛; 陈红齐

    2014-01-01

    香格里拉县桑那水库是云南省第一座在高海拔3300 m的高寒地区修建的中型水库,当地冬季气温低(最低气温-27.4℃),对坝基开挖、填筑、混凝土浇筑施工带来很大影响,设计提出:1)混凝土盖板及坝基保护采取引水保护,水与岸坡结合部位易形成冰冻,对这部分采取塑料薄膜加石碴覆盖;2)土料避开低温期施工,在施工中随时检查粘土含水量,在料场采取挖排水沟,开挖过的土料场上以及填筑好的防渗心墙上覆盖三色塑料薄膜加渣料作保护等保温防冻措施;3)在永久暴露混凝土表面配置温度钢筋,浇筑混凝土时掺入抗冻剂、减水剂、速凝剂,同时采取保温措施。%Located in Shangri-La county,Sangna reservoir, a medium-sized water-conservancy project,is the first medium reservoir built in extremely cold areas at an altitude of 3 300 meters. The local temperature in winter is low (the minimum temperature is 27.4 degrees),which severely affects the founda-tion excavation,filling and concrete pouring for the damming The design in this paper proposes the following countermeasures:1) we could use water to protect the concrete cover and dam foundation;and cover the combination parts between water and bank(where freezing can be easily formed)with plastic film and ballast;2)As for the earth material,we could avoid construct-ing in low temperatures and check the clay moisture frequently during construction;and dig ditches in the stock field and cover the field for anti-freezing protection with three-color plastic film and ballast;3)we could take measures to keep the concrete warm in the process of pouring by mixing it with antifreeze agent,water reducing agent and at the same time use temperature rebar on the surface of the permanent exposed concrete.

  17. Effect of surface catalycity on high-altitude aerothermodynamics of reentry vehicles

    Science.gov (United States)

    Molchanova, A. N.; Kashkovsky, A. V.; Bondar, Ye. A.

    2016-10-01

    This work is aimed at the development of surface chemistry models for the Direct Simulation Monte Carlo (DSMC) method applicable to non-equilibrium high-temperature flows about reentry vehicles. Probabilities of the surface processes dependent on individual properties of each particular molecule are determined from the macroscopic reaction rate data. Two different macroscopic finite rate sets are used for construction of DSMC surface recombination models. The models are implemented in the SMILE++ software system for DSMC computations. A comparison with available experimental data is performed. Effects of surface recombination on the aerothermodynamics of a blunt body at high-altitude reentry conditions are numerically studied with the DSMC method.

  18. An appraisal of precipitation distribution in the high-altitude catchments of the Indus basin.

    Science.gov (United States)

    Dahri, Zakir Hussain; Ludwig, Fulco; Moors, Eddy; Ahmad, Bashir; Khan, Asif; Kabat, Pavel

    2016-04-01

    Scarcity of in-situ observations coupled with high orographic influences has prevented a comprehensive assessment of precipitation distribution in the high-altitude catchments of Indus basin. Available data are generally fragmented and scattered with different organizations and mostly cover the valleys. Here, we combine most of the available station data with the indirect precipitation estimates at the accumulation zones of major glaciers to analyse altitudinal dependency of precipitation in the high-altitude Indus basin. The available observations signified the importance of orography in each sub-hydrological basin but could not infer an accurate distribution of precipitation with altitude. We used Kriging with External Drift (KED) interpolation scheme with elevation as a predictor to appraise spatiotemporal distribution of mean monthly, seasonal and annual precipitation for the period of 1998-2012. The KED-based annual precipitation estimates are verified by the corresponding basin-wide observed specific runoffs, which show good agreement. In contrast to earlier studies, our estimates reveal substantially higher precipitation in most of the sub-basins indicating two distinct rainfall maxima; 1st along southern and lower most slopes of Chenab, Jhelum, Indus main and Swat basins, and 2nd around north-west corner of Shyok basin in the central Karakoram. The study demonstrated that the selected gridded precipitation products covering this region are prone to significant errors. In terms of quantitative estimates, ERA-Interim is relatively close to the observations followed by WFDEI and TRMM, while APHRODITE gives highly underestimated precipitation estimates in the study area. Basin-wide seasonal and annual correction factors introduced for each gridded dataset can be useful for lumped hydrological modelling studies, while the estimated precipitation distribution can serve as a basis for bias correction of any gridded precipitation products for the study area

  19. High altitude dives from 7000 to 14,200 feet in the Himalayas.

    Science.gov (United States)

    Sahni, T K; John, M J; Dhall, A; Chatterjee, A K

    1991-07-01

    Indian Navy divers carried out no-decompression dives at altitudes of 7000 to 14,200 ft (2134-4328 m) in the Nilgiris and Himalayas from May to July 1988. Seventy-eight dives on air and 22 dives on oxygen were carried out at various altitudes. The final dives were at Lake Pangong Tso (4328 m) in Ladakh, Himalayas, to a maximum of 140 feet of sea water (fsw) [42.6 meters of sea water (msw)] equivalent ocean depth in minimum water temperature of 2 degrees C. Oxygen diving at 14,200 ft (4328 m) was not successful. Aspects considered were altitude adaptation, diminished air pressure diving, hypothermia, and remote area survival. Depths at altitude were converted to depths at sea level and were applied to the Royal Navy air tables. Altitude-related manifestations, hypoxia, hypothermia, suspected oxygen toxicity, and equipment failure were observed. It is concluded that stress is due to effects of altitude and cold on man and equipment, as well as changes in diving procedures when diving at high altitudes. Equivalent air depths when applied to Royal Navy tables could be considered a safe method for diving at altitudes.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    represent strong candidates for altitude adaptation, were identified. The strongest signal of natural selection came from endothelial Per-Arnt-Sim (PAS) domain protein 1 (EPAS1), a transcription factor involved in response to hypoxia. One single-nucleotide polymorphism (SNP) at EPAS1 shows a 78% frequency...... difference between Tibetan and Han samples, representing the fastest allele frequency change observed at any human gene to date. This SNP's association with erythrocyte abundance supports the role of EPAS1 in adaptation to hypoxia. Thus, a population genomic survey has revealed a functionally important locus...

  1. High altitude and hemoglobin function in the vultures Gyps rueppelli and Aegypius monachus

    DEFF Research Database (Denmark)

    Weber, Roy E.; Hiebl, Inge; Braunitzer, Gerhard

    1988-01-01

    structures of the constituent polypeptide chains to trace molecular adaptations to high-altitude respiration, and to physiological factors (pulmonary hypoxia and hypocapnia, body temperature shifts, and lung and nasal gas and heat exchange) to discern their possible survival value at altitudes of 11300 m.......Functional characteristics of the stripped composite hemoglobins (Hbs) of lhevultures Gyps rueppellii and Aegypills monachus that can fly at extremely high altitudes, and of component Hbs of G. rueppellii are reported, in relation to influences of pH, temperalure and inositol hexaphosphate. G...

  2. On the Survival of High-Altitude Open Clusters within the Milky Way Galaxy Tides

    CERN Document Server

    Martinez-Medina, L A; Peimbert, A; Moreno, E

    2016-01-01

    It is a common assumption that high-altitude open clusters live longer compared with clusters moving close to the Galactic plane. This is because at high altitudes, open clusters are far from the disruptive effects of in-plane substructures, such as spiral arms, molecular clouds and the bar. However, an important aspect to consider in this scenario is that orbits of high-altitude open clusters will eventually cross the Galactic plane, where the vertical tidal field of the disk is strong. In this work we simulate the interaction of open clusters with the tidal field of a detailed Milky Way Galactic model at different average altitudes and galactocentric radii. We find that the life expectancy of clusters decreases as the maximum orbital altitude increases and reaches a minimum at altitudes of approximately 600 pc. Clusters near the Galactic plane live longer because they do not experience strong vertical tidal shocks from the Galactic disk; then, for orbital altitudes higher than 600 pc, clusters start again t...

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

    Data.gov (United States)

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

  4. Thermally Stable Catalytic Combustors for Very High Altitude Airbreathing Propulsion Project

    Data.gov (United States)

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

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

    Science.gov (United States)

    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.

  6. The Impact of Moderate-Altitude Staging on Pulmonary Arterial Hemodynamics after Ascent to High Altitude

    Science.gov (United States)

    2010-01-01

    pressure ( Pao2 ) and arterial oxygenation saturation (Sao2) were measured at each time point. Compared to mean PAP at SL (mean SD, 14 3 mmHg), mean PAP...increased after DA to 37 8 mmHg (D¼ 24 10 mmHg, p< 0.001) and was negatively correlated with both Pao2 (r 2¼ 0.57, p¼ 0.011) and Sao2 (r2¼ 0.64, p...subcostal view. Assessment of oxygenation The primary indexes of oxygenation in this study were alveolar oxygen pressure ( Pao2 ) and arterial oxygen

  7. Expression of HIF-1α and Its Target Genes in the Nanorana parkeri Heart:Implications for High Altitude Adaptation

    Institute of Scientific and Technical Information of China (English)

    Qiong ZHANG; Xingzhi HAN; Yinzi YE; Robert H S KRAUS; Liqing FAN; Le YANG; Yi TAO

    2016-01-01

    Hypoxia-inducible factor 1 alpha (HIF-1α) and its target genes vascular endothelial growth factor (VEGF) and transferrins (TF) play an important role in native endothermic animals’ adaptation to the high altitude environments. For ectothermic animals – especially frogs – it remains undetermined whether HIF-1α and its target genes (VEGF and TF) play an important role in high altitude adaptation, too. In this study, we compared the gene sequences and expression of HIF-1α and its target genes (VEGF and TF) between three Nanorana parkeri populations from different altitudes (3008 m a.s.l., 3440 m a.s.l. and 4312 m a.s.l.). We observed that the cDNA sequences of HIF-1A exhibited high sequence similarity (99.38%) among the three altitudinally separated populations; but with increasing altitude, the expression of HIF-1A and its target genes (VEGF and TF) increased significantly. These results indicate that HIF-1αplays an important role in N. parkeri adaptation to the high altitude, similar to its role in endothermic animals.

  8. ROCK2 and MYLK variants and high-altitude pulmonary edema

    Directory of Open Access Journals (Sweden)

    Sikri G

    2016-08-01

    Full Text Available Gaurav Sikri, Srinivasa Bhattachar Department of Physiology, Armed Forces Medical College, Pune, Maharashtra, IndiaWe have read the article titled “ROCK2 and MYLK variants under hypobaric hypoxic environment of high altitude associate with high altitude pulmonary edema and adaptation” by Pandey et al1 with profound interest. View the original paper by Pandey and colleagues.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Sikri G

    2015-12-01

    Full Text Available Gaurav Sikri, Anirban Bhattacharya Department of Physiology, Armed Forces Medical College, Wanowarie, Pune, IndiaWe read with great interest the review article titled “Wilderness medicine at high altitude: recent developments in the field” by Shah et al.1 The authors have comprehensively summarized the recent advances in the field of high altitude medicine relevant to sports and travel medicine. However, Shah et al have described potential drugs for management of high-altitude illnesses, such as acute mountain sickness (AMS, high altitude cerebral edema, and high altitude pulmonary edema (HAPE as one group under the section “Novel drug treatment for AMS”. The pathophysiologies of these two sets of diseases (AMS/high altitude cerebral edema as one and HAPE as another set are different2 and hence it would have been nice to have had the novel drugs described separately to elucidate the therapeutic approach for the two different classes of diseases.View original paper by Shah et al.

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

    Directory of Open Access Journals (Sweden)

    Jiří Suchý

    2015-03-01

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

  12. NUCLEOTIDE COMPARISON OF GDF9 GENE IN INDIAN YAK AND GADDI GOAT: HIGH ALTITUDE LIVESTOCK ANIMALS

    Directory of Open Access Journals (Sweden)

    Lakshya Veer Singh

    2013-06-01

    Full Text Available The present study was undertaken to characterize exon 1 and exon 2 sequence of one of fecundity genes: GDF9 (Growth differentiation factor 9, in high altitude livestock animal (Yak and Gaddi goat. Six nucleotide differences were identified between sheep (AF078545 and goats (EF446168 in exon 1 and exon 2. Sequencing revealed nine novel single nucleotide mutations in exon 1 and exon 2 of Indian yak that compared with Bos taurus (GQ922451. These results preliminarily showed that the GDF9 gene might be a major gene that influences prolificacy of Gaddi goats and Indian yak.

  13. Screening the Raspberry Varieties in High Altitude and Studying on Nutrition Composition of Raspberry%高海拔地区树莓品种筛选及营养成分研究

    Institute of Scientific and Technical Information of China (English)

    杨正松; 和加卫; 和志娇; 李燕; 毕海林; 黄杏娥

    2013-01-01

    In order to select the suitable high altitude cultivated varieties of raspberry, the author screened four raspberry varieties at high altitude and analyzed the nutrition composition of raspberry. The results showed that the soluble solid content, reducing sugar, total sugar and other nutrients of the same variety gradually increased with altitude from high to low. But the content of vitamin C decreased gradually. The higher the temperature, the higher the total sugar content it had. The content of soluble solids and reducing sugar of 'Chilcotin' blackberry was highest, and the taste was best in the four species. It was suitable for planting in high altitude area. The Fall Gold fruit period was long and taste was moderate. But it was easily broken and not easily transported. It was suitable for processing and growing around in the environs of the city.%为了筛选适合高海拔地区栽培的树莓品种,在高海拔地区对4个树莓品种进行筛选及营养成分的比较分析.结果表明,同一品种不同海拔,海拔由高到低,可溶性固形物、还原糖、总糖等营养成分逐渐升高,维生素C含量逐渐降低,气温越高含总糖量越高.4个品种中,‘奇里考特’的可溶性固形物含量最高,还原糖最高,口感最好,适合在高海拔地区推广种植.而‘秋金’的果期长,口感适中,但易破碎,不宜运输,适宜加工,适宜在城市周围适宜种植.

  14. Effects of slow deep breathing at high altitude on oxygen saturation, pulmonary and systemic hemodynamics.

    Directory of Open Access Journals (Sweden)

    Grzegorz Bilo

    Full Text Available Slow deep breathing improves blood oxygenation (Sp(O2 and affects hemodynamics in hypoxic patients. We investigated the ventilatory and hemodynamic effects of slow deep breathing in normal subjects at high altitude. We collected data in healthy lowlanders staying either at 4559 m for 2-3 days (Study A; N = 39 or at 5400 m for 12-16 days (Study B; N = 28. Study variables, including Sp(O2 and systemic and pulmonary arterial pressure, were assessed before, during and after 15 minutes of breathing at 6 breaths/min. At the end of slow breathing, an increase in Sp(O2 (Study A: from 80.2±7.7% to 89.5±8.2%; Study B: from 81.0±4.2% to 88.6±4.5; both p<0.001 and significant reductions in systemic and pulmonary arterial pressure occurred. This was associated with increased tidal volume and no changes in minute ventilation or pulmonary CO diffusion. Slow deep breathing improves ventilation efficiency for oxygen as shown by blood oxygenation increase, and it reduces systemic and pulmonary blood pressure at high altitude but does not change pulmonary gas diffusion.

  15. Development of Techniques for the In Situ Observation of OH and HO2 for Studies of the Impact of High-Altitude Supersonic Aircraft on the Stratosphere

    Science.gov (United States)

    Anderson, James G.

    1994-01-01

    This three-year project supported the construction, calibration, and deployment of a new instrument to measure the OH and HO2 radicals on the NASA ER-2 aircraft. The instrument has met and exceeded all of its design goals. The instrumentation represents a true quantum leap in performance over that achieved in previous HO(x) instruments built in our group. Sensitivity for OH was enhanced by over two orders of magnitude as the weight fell from approximately 1500 to less than 200 Kg. Reliability has been very high: HO(x) data are available for all flights during the first operational mission, the Stratospheric Photochemistry, Aerosols, and Dynamics Expedition (SPADE). The results of that experiment have been reported in the scientific literature and at conferences. Additionally, measurements of H2O and O3 were made and have been reported in the scientific literature. The measurements demonstrate the important role that OH and HO2 play in determining the concentration of ozone in the lower stratosphere. During the SPADE campaign, the measurements demonstrate that the catalytic removal is dominated by processes involving the odd-hydrogen and halogen radical extremely important constraint for photochemical models that are being used to assess the potential deleterious effects of super-sonic aircraft effluent on the burden of stratospheric ozone. A list of the papers that came from this research are included, along with a copy of the paper, 'Aircraft-borne, laser-induced fluorescence instrument for the in situ detection of hydroxyl and hydroperoxyl radicals'.

  16. A necklace of pearl in high altitude medicine and hypoxic physiology in Yushu Earthquake

    Institute of Scientific and Technical Information of China (English)

    Fan Ming

    2013-01-01

    During Yushu Earthquake,a large number of rescuers flocked to the mountainous quake areas.Under such a very specific circumstance,a high incidence of acute altitude illness was observed in rescuers who rapidly traveled from near sea level to an altitude of 4 000 m.It is evident that acute altitude illness leads to a significant human and economic toll,and also seriously influences the mountain rescue operation.So what does this teach us about mountain rescue in Yushu? Professor Wu Tianyi and many other authors collected shining points of the experiences and drew the lessons from the Yushu Earthquake into this special issue in Engineering Sciences which is like to thread pearl beads for a necklace.What readers learn from this special issue will have implications for the health and well-being of all high altitude populations all over the world.

  17. Implementation of a Novel Flight Tracking and Recovery Package for High Altitude Ballooning Missions

    Science.gov (United States)

    Fatima, Aqsa; Nekkanti, Sanjay; Mohan Suri, Ram; Shankar, Divya; Prasad Nagendra, Narayan

    High altitude ballooning is typically used for scientific missions including stratospheric observations, aerological observations, and near space environment technology demonstration. The usage of stratospheric balloons is a cost effective method to pursue several scientific and technological avenues against using satellites in the void of space. Based on the Indian Institute of Astrophysics (IIA) ballooning program for studying Comet ISON using high altitude ballooning, a cost effective flight tracking and recovery package for ballooning missions has been developed using open source hardware. The flight tracking and recovery package is based on using Automatic Packet Reporting System (APRS) and has a redundant Global System for Mobile Communications (GSM) based Global Positioning System (GPS) tracker. The APRS based tracker uses AX.25 protocol for transmission of the GPS coordinates (latitude, longitude, altitude, time) alongside the heading and health parameters of the board (voltage, temperature). APRS uses amateur radio frequencies where data is transmitted in packet messaging format, modulated by radio signals. The receiver uses Very High Frequency (VHF) transceiver to demodulate the APRS signals. The data received will be decoded using MixW (open source software). A bridge will be established between the decoding software and the APRS software. The flight path will be predicted before the launch and the real time position co-ordinates will be used to obtain the real time flight path that will be uploaded online using the bridge connection. We also use open source APRS software to decode and Google Earth to display the real time flight path. Several ballooning campaigns do not employ payload data transmission in real time, which makes the flight tracking and package recovery vital for data collection and recovery of flight instruments. The flight tracking and recovery package implemented in our missions allow independent development of the payload package

  18. Prototype detector development for measurement of high altitude Martian dust using a future orbiter platform

    Science.gov (United States)

    Pabari, Jayesh; Patel, Darshil; Chokhawala, Vimmi; Bogavelly, Anvesh

    2016-07-01

    Dust devils mostly occur during the mid of Southern hemisphere summer on Mars and play a key role in the background dust opacity. Due to continuous bombardment of micrometeorites, secondary ejecta come out from the Moons of the Mars and can easily escape. This phenomenon can contribute dust around the Moons and therefore, also around the Mars. Similar to the Moons of the Earth, the surfaces of the Martian Moons get charged and cause the dust levitation to occur, adding to the possible dust source. Also, interplanetary dust particles may be able to reach the Mars and contribute further. It is hypothesized that the high altitude Martian dust could be in the form of a ring or tori around the Mars. However, no such rings have been detected to the present day. Typically, width and height of the dust torus is ~5 Mars radii wide (~16950 km) in both the planes as reported in the literature. 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, a langmuir probe cannot explain the source of such dust particles. It is a puzzling question to the space scientist how dust has reached to such high altitudes. A dedicated dust instrument on future Mars orbiter may be helpful to address such issues. To study origin, abundance, distribution and seasonal variation of Martian dust, a Mars Orbit Dust Experiment (MODEX) is proposed. In order to measure the Martian dust from a future orbiter, design of a prototype of an impact ionization dust detector has been initiated at PRL. This paper presents developmental aspects of the prototype dust detector and initial results. The further work is underway.

  19. Relative Match Intensities at High Altitude in Highly-Trained Young Soccer Players (ISA3600

    Directory of Open Access Journals (Sweden)

    Martin Buchheit

    2015-03-01

    Full Text Available To compare relative match intensities of sea-level versus high-altitude native soccer players during a 2-week camp at 3600 m, data from 7 sea-level (Australian U17 National team, AUS and 6 high-altitude (a Bolivian U18 team, BOL native soccer players were analysed. Two matches were played at sea-level and three at 3600 m on Days 1, 6 and 13. The Yo-Yo Intermittent recovery test (vYo-YoIR1 was performed at sea-level, and on Days 3 and 10. Match activity profiles were measured via 10-Hz GPS. Distance covered >14.4 km.h-1 (D>14.4 km·h-1 and >80% of vYo-YoIR1 (D>80%vYo-YoIR1 were examined. Upon arrival at altitude, there was a greater decrement in vYo-YoIR1 (Cohen’s d +1.0, 90%CL ± 0.8 and D>14.4 km·h-1 (+0.5 ± 0.8 in AUS. D>14.4 km.h-1 was similarly reduced relative to vYo-YoIR1 in both groups, so that D>80%vYo-YoIR1 remained similarly unchanged (-0.1 ± 0.8. Throughout the altitude sojourn, vYo-YoIR1 and D>14.4 km·h-1 increased in parallel in AUS, so that D>80%vYo-YoIR1 remained stable in AUS (+6.0%/match, 90%CL ± 6.7; conversely D>80%vYo-YoIR1 decreased largely in BOL (-12.2%/match ± 6.2. In sea-level natives competing at high-altitude, changes in match running performance likely follow those in high-intensity running performance. Bolivian data confirm that increases in ‘fitness’ do not necessarily translate into greater match running performance, but rather in reduced relative exercise intensity.

  20. Oxygen ion energization by waves in the high altitude cusp and mantle

    Directory of Open Access Journals (Sweden)

    M. Waara

    2012-09-01

    Full Text Available We present a comparative study of low frequency electric field spectral densities and temperatures observed by the Cluster spacecraft in the high altitude cusp/mantle region. We compare the relation between the O+ temperature and wave intensity at the oxygen gyrofrequency at each measurement point and find a clear correlation. The trend of the correlation agrees with the predictions by both an asymptotic mean-particle theory and a test-particle approach. The perpendicular to parallel temperature ratio is also consistent with the predictions of the asymptotic mean-particle theory. At times the perpendicular temperature is significantly higher than predicted by the models. A simple study of the evolution of the particle distributions (conics at these altitudes indicates that enhanced perpendicular temperatures would be observed over many RE after heating ceases. Therefore, sporadic intense heating is the likely explanation for cases with high temperature and comparably low wave activity. We observe waves of sufficient amplitude to explain the highest observed temperatures, while the theory in general overestimates the temperature associated with the highest observed wave activity, indicating that such high wave activity is very sporadic.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-08-01

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

  2. High Altitude Bird Migration at Temperate Latitudes: A Synoptic Perspective on Wind Assistance

    OpenAIRE

    2013-01-01

    At temperate latitudes the synoptic patterns of bird migration are strongly structured by the presence of cyclones and anticyclones, both in the horizontal and altitudinal dimensions. In certain synoptic conditions, birds may efficiently cross regions with opposing surface wind by choosing a higher flight altitude with more favourable wind. We observed migratory passerines at mid-latitudes that selected high altitude wind optima on particular nights, leading to the formation of structured mig...

  3. Decreased plasma soluble erythropoietin receptor in high-altitude excessive erythrocytosis and Chronic Mountain Sickness

    OpenAIRE

    Villafuerte, Francisco C.; Macarlupú, José Luis; Anza-Ramírez, Cecilia; Corrales-Melgar, Daniela; Vizcardo-Galindo, Gustavo; Corante, Noemí; León-Velarde, Fabiola

    2014-01-01

    Excessive erythrocytosis (EE) is the hallmark of chronic mountain sickness (CMS), a prevalent syndrome in high-altitude Andean populations. Although hypoxemia represents its underlying stimulus, why some individuals develop EE despite having altitude-normal blood erythropoietin (Epo) concentration is still unclear. A soluble form of the Epo receptor (sEpoR) has been identified in human blood and competes directly for Epo with its membrane counterpart (mEpoR). Thus, reduced levels of circulati...

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

    Directory of Open Access Journals (Sweden)

    Jiří Flousek

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  6. Regional differences in the cerebral blood flow velocity response to hypobaric hypoxia at high altitudes.

    Science.gov (United States)

    Feddersen, Berend; Neupane, Pritam; Thanbichler, Florian; Hadolt, Irmgard; Sattelmeyer, Vera; Pfefferkorn, Thomas; Waanders, Robb; Noachtar, Soheyl; Ausserer, Harald

    2015-11-01

    Symptoms of acute mountain sickness (AMS) may appear above 2,500 m altitude, if the time allowed for acclimatization is insufficient. As the mechanisms underlying brain adaptation to the hypobaric hypoxic environment are not fully understood, a prospective study was performed investigating neurophysiological changes by means of near infrared spectroscopy, electroencephalograpy (EEG), and transcranial doppler sonography at 100, 3,440 and 5,050 m above sea level in the Khumbu Himal, Nepal. Fourteen of the 26 mountaineers reaching 5,050 m altitude developed symptoms of AMS between 3,440 and 5,050 m altitude (Lake-Louise Score ⩾3). Their EEG frontal beta activity and occipital alpha activity increased between 100 and 3,440 m altitude, i.e., before symptoms appeared. Cerebral blood flow velocity (CBFV) in the anterior and middle cerebral arteries (MCAs) increased in all mountaineers between 100 and 3,440 m altitude. During further ascent to 5,050 altitude, mountaineers with AMS developed a further increase in CBFV in the MCA, whereas in all mountaineers CBFV decreased continuously with increasing altitude in the posterior cerebral arteries. These results indicate that hypobaric hypoxia causes different regional changes in CBFV despite similar electrophysiological changes.

  7. GuMNet - A high altitude monitoring network in the Sierra de Guadarrama (Madrid, Spain)

    Science.gov (United States)

    Santolaria-Canales, Edmundo

    2016-04-01

    The Guadarrama Monitoring Network (GuMNet) is an observational infrastructure focused on monitoring the state of the atmosphere and the ground in the Sierra de Guadarrama, 50 km NW of the city of Madrid. The network is composed of10 stations ranging from low altitude (900 m a.s.l.) to high mountain climate (2400 m a.s.l.). The atmospheric instrumentation includes sensors for air temperature, air humidity, 4-component net radiation, precipitation, snow height and wind speed and direction. The surface and subsurface infrastructure includes temperature and humidity sensors distributed in 9 trenches up to a maximum of 1 m depth and additionally temperature sensors in 15 PVC cased boreholes down to 20 m and 2 m with a higher vertical resolution close to the surface. All stations are located in exposed open areas except for one site that is in a forested area for measuring air-ground fluxes under forest conditions. High altitude sites are focused on periglacial areas and lower altitude sites have emphasis on pastures. One of the low altitude sites is equipped with a 10 m high tower with 3D sonic anemometers and a CO2/H2O analyzer that will allow the sampling of wind profiles and H2O and CO2 eddy covariance fluxes, important for estimation of CO2 and energy exchanges over complex vegetated surfaces. The network is connected via general packet radio service to the central lab in the Campus of Excellence of Moncloa and management software has been developed to handle the operation of the infrastructure. The data provided by GuMNet will help to improve the characterization of atmospheric variability from turbulent scales to meteorology and climate at high mountain areas, as well as land-atmosphere interactions. The network information aims at meeting the needs of accuracy to be used for biological, agricultural, hydrological, meteorological and climatic investigations in this area with relevance for ecosystem oriented studies. This setup will complement the broader network

  8. Measurement of the Space Radiation Dose for the Flight Aircrew at High-Altitude

    Science.gov (United States)

    Lee, Jaewon; Park, Inchun; Kim, Junsik; Lee, Jaejin; Hwang, Junga; Kim, Young-chul

    2014-03-01

    This paper describes an experimental approach to evaluate the effective doses of space radiations at high-altitude by combining the measured data from the Liulin-6K spectrometer loaded onto the air-borne RC-800 cockpit and the calculated data from CARI-6M code developed by FAA. In this paper, 15 exposed dose experiments for the flight missions at a highaltitude above 10 km and 3 experiments at a normal altitude below 4 km were executed over the Korean Peninsula in 2012. The results from the high-altitude flight measurements show a dramatic change in the exposed doses as the altitude increases. The effective dose levels (an average of 15.27 mSv) of aircrew at the high-altitude are an order of magnitude larger than those (an average of 0.30 mSv) of the normal altitude flight. The comparison was made between the measure dose levels and the calculated dose levels and those were similar each other. It indicates that the annual dose levels of the aircrew boarding RC- 800 could be above 1 mSv. These results suggest that a proper procedure to manage the exposed dose of aircrew is required for ROK Air Force.

  9. A GIS-aided response model of high-altitude permafrost to global change

    Institute of Scientific and Technical Information of China (English)

    李新; 程国栋

    1999-01-01

    Two models are used to simulate the high-altitude permafrost distribution on the Qinghai-Xizang Plateau. The two models are the "altitude model", a Gaussian distribution function used to describe the latitudinal zonation of permafrost based on the three-dimensional rules of high-altitude permafrost, and the "frost number model", a dimensionless ratio defined by manipulation of freezing and thawing degree-day sums. The results show that the "altitude model" can simulate the high-altitude permafrost distribution under present climate conditions accurately. Given the essential hypotheses and using the GCM scenarios from HADCM2, the "altitude model" is used for predicting the permafrost distribution change on the Qinghai-Xizang Plateau. The results show that the permafrost on the plateau will not change significantly during 20—50 a, the percentage of the total disappeared area will not be over 19%. However, by the year 2099, if the air temperature increases by an average of 2.91℃ on the plateau, the decre

  10. Prehistoric Human Dispersal to the Tibetan Plateau and Adaptation to the High Altitude Environment

    Science.gov (United States)

    Zhang, Dongju; Dong, Guanghui; Chen, Fahu

    2016-04-01

    Human history of the Tibetan Plateau and human adaptation to the high altitude environment is hotly debated in the past decade among archaeological, anthropological, genetic, and even past climate change studies. Based on previous studies on the Tibetan Plateau and our own archaeological studies in northeastern Tibetan Plateau (NETP), we propose that human migrated to the Tibetan Plateau from the last Deglacial period to late Holocene mainly from North China via Yellow River valley and its tributary valleys in NETP. This migration is constituted of four stages (Upper Paleolithic, Epi-Paleolithic, Neolithic and Bronze Age) when human adapted to the high altitude environment and climate change with different strategies and techniques. Particularly, the prevail of microlithic technology in North China provoked hunter-gatherers' first visit to the NETP in relatively ameliorated last Deglacial period, and the quick development of millet farming and subsequent mixed barley-wheat farming and sheep herding facilitated farmers and herders permanently settled in NETP, even above 3000 masl, during mid- and late Holocene.

  11. Atmospheric sub-3 nm particles at high altitudes

    Directory of Open Access Journals (Sweden)

    S. Mirme

    2010-01-01

    Full Text Available Formation of new atmospheric aerosol particles is known to occur almost all over the world and the importance of these particles to climate and air quality has been recognized. Recently, it was found that atmospheric aerosol particle formation begins at the diameter of around 1.5–2.0 nm and a pool of sub-3 nm atmospheric particles – consisting of both charged and uncharged ones – was observed at the ground level. Here, we report on the first airborne observations of the pool of sub-3 nm neutral atmospheric particles. Between 2 and 3 nm, their concentration is roughly two orders of magnitude larger than that of the ion clusters, depending slightly on the altitude. Our findings indicate that new particle formation takes place throughout the tropospheric column up to the tropopause. Particles were found to be formed via neutral pathways in the boundary layer, and there was no sign of an increasing role by ion-induced nucleation toward the upper troposphere. Clouds, while acting as a source of sub-10 nm ions, did not perturb the overall budget of atmospheric clusters or particles.

  12. Atmospheric sub-3 nm particles at high altitudes

    Directory of Open Access Journals (Sweden)

    S. Mirme

    2009-09-01

    Full Text Available Formation of new atmospheric aerosol particles is known to occur almost all over the world and the importance of these particles to climate and air quality has been recognized. Recently, it was found that atmospheric aerosol formation begins at particle diameter of around 1.5–2.0 nm and a pool of sub-3 nm atmospheric particles – consisting of both charged and uncharged ones – was observed at the ground level. Here, we report on the first airborne observations of the pool of sub-3 nm neutral atmospheric particles. Between 2 and 3 nm, their concentration is roughly two orders of magnitude larger than that of the ion clusters, depending slightly on the altitude. Our findings indicate that new particle formation takes place actively throughout the tropospheric column up to the tropopause. Particles were found to be formed via neutral pathways in the boundary layer, and there was no sign of an increasing role by ion-induced nucleation toward the upper troposphere. Clouds, while acting as a source of sub-10 nm ions, did not perturb the overall budget of atmospheric clusters or particles.

  13. Iodine isotopes (127I and 129I) in aerosols at high altitude Alp stations.

    Science.gov (United States)

    Jabbar, Tania; Steier, Peter; Wallner, Gabriele; Priller, Alfred; Kandler, Norbert; Kaiser, August

    2012-08-21

    Concentrations of gases and particulate matter have been proven to be affected by meteorological and geographical variables from urban locations to high mountain clean air sites. Following our previous research in Vienna, we summarize here new findings about concentration levels of iodine isotopes in aerosols collected at two Alpine meteorological stations, Sonnblick (Austria) and Zugspitze (Germany) during 2001. The present study mainly focuses on the effect of altitude on the anthropogenic concentration of (129)I and on the isotopic ratio (129)I/(127)I. Iodine was separated from matrix elements by using either an anion exchange method or solvent extraction, and was analyzed by ICP-MS and AMS. Over the altitude change from Vienna to Zugspitze and Sonnblick (202 m to 2962 m and 3106 m above sea level), stable iodine level decreased from an average of 0.94 ng m(-3) to 0.52 ng m(-3) and 0.62 ng m(-3), respectively. Similarly, (129)I concentrations at both Alpine stations were about 1 order of magnitude lower (10(4) atoms m(-3)) than values obtained for Vienna (10(5) atoms m(-3)) and reveal a strong vertical concentration gradient of (129)I. A high degree of variability is observed, which is due to wide variation in the origin of air masses. Furthermore, air trajectory analysis demonstrates the importance of large scale air transport mostly from southeast Europe for influencing Sonnblick whereas influence from northwest Europe is strong at Zugspitze. In contrast to (129)I, a higher concentration of (7)Be was found at higher altitude stations compared to Vienna which probably results from its production in the upper atmosphere.

  14. Difference in blood microcirculation recovery between normal frostbite and high-altitude frostbite

    Directory of Open Access Journals (Sweden)

    Ming-ke JIAO

    2017-02-01

    Full Text Available Objective To determine the difference in blood microcirculation recovery between normal frostbite and high-altitude frostbite during the wound healing. Methods Twenty four male rats were randomly divided into control group (n=8, normal frostbite group (n=8, and high-altitude group (n=8. The normal frostbite group rats were frozen to produce mid-degree frostbite models by controlling the freezing time with liquid nitrogen penetration equipment. The high-altitude frostbite group rats were acclimated to a hypoxic and low-pressure environment for 1 week, and then the high-altitude frostbite models were constructed by the same way with liquid nitrogen penetration apparatus. On days 3, 7, 11, 15, 19, and 23 after modeling, the recovery situation of blood circulation of each group was observed with contrast ultrasonography by injecting SonoVue micro-bubble into rats' tail. Finally, the micro-bubble concentration (MC was calculated to confirm the blood circulation recovery with software Image Pro. Results At different time points, the wound area of the high-altitude frostbite group was bigger than that of the normal frostbite group, and the MC of control group was always about (27±0.2×109/ml. On day 3, 7, 11, 15, 19, and 23, the MC was significantly lower in the high-altitude frostbite group than in the control group and normal frostbite group (P<0.05. The MC of normal frostbite group was significantly lower than that of the control group on day 3, 7, 11, 15 and 19 (P<0.05. In addition, no obvious difference in MC was found between normal group and control group on the 23th day (P<0.05. Conclusion The blood microcirculation recovery after high-altitude frostbite is significantly slower than the normal frostbite. DOI: 10.11855/j.issn.0577-7402.2017.01.13

  15. Control of breathing and the circulation in high-altitude mammals and birds.

    Science.gov (United States)

    Ivy, Catherine M; Scott, Graham R

    2015-08-01

    Hypoxia is an unremitting stressor at high altitudes that places a premium on oxygen transport by the respiratory and cardiovascular systems. Phenotypic plasticity and genotypic adaptation at various steps in the O2 cascade could help offset the effects of hypoxia on cellular O2 supply in high-altitude natives. In this review, we will discuss the unique mechanisms by which ventilation, cardiac output, and blood flow are controlled in high-altitude mammals and birds. Acclimatization to high altitudes leads to some changes in respiratory and cardiovascular control that increase O2 transport in hypoxia (e.g., ventilatory acclimatization to hypoxia). However, acclimatization or development in hypoxia can also modify cardiorespiratory control in ways that are maladaptive for O2 transport. Hypoxia responses that arose as short-term solutions to O2 deprivation (e.g., peripheral vasoconstriction) or regional variation in O2 levels in the lungs (i.e., hypoxic pulmonary vasoconstriction) are detrimental at in chronic high-altitude hypoxia. Evolved changes in cardiorespiratory control have arisen in many high-altitude taxa, including increases in effective ventilation, attenuation of hypoxic pulmonary vasoconstriction, and changes in catecholamine sensitivity of the heart and systemic vasculature. Parallel evolution of some of these changes in independent highland lineages supports their adaptive significance. Much less is known about the genomic bases and potential interactive effects of adaptation, acclimatization, developmental plasticity, and trans-generational epigenetic transfer on cardiorespiratory control. Future work to understand these various influences on breathing and circulation in high-altitude natives will help elucidate how complex physiological systems can be pushed to their limits to maintain cellular function in hypoxia.

  16. Assessment of roughness length schemes implemented within the Noah land surface model for high-altitude regions

    NARCIS (Netherlands)

    Zheng, D.; Velde, van der R.; Su, Z.; Booij, M.J.; Hoekstra, A.Y.; Wen, J.

    2014-01-01

    Current land surface models still have difficulties with producing reliable surface heat fluxes and skin temperature (Tsfc) estimates for high-altitude regions, which may be addressed via adequate parameterization of the roughness lengths for momentum (z0m) and heat (z0h) transfer. In this study, th

  17. Water level changes of high altitude lakes in Himalaya–Karakoram from ICESat altimetry

    Indian Academy of Sciences (India)

    Priyeshu Srivastava; Rakesh Bhambri; Prashant Kawishwar; D P Dobhal

    2013-12-01

    Himalaya–Karakoram (H–K) region hosts large number of high altitude lakes but are poorly gauged by in-situ water level monitoring method due to tough terrain conditions and poor accessibility. After the campaigns of ICESat during 2003–2009, now it is possible to achieve lake levels at decimetre accuracy. Therefore, in present study, high altitude lake levels were observed using ICESat/GLAS altimetry in H–K between 2003 and 2009 to generate baseline information. The study reveals that out of 13 lakes, 10 lakes show increasing trend of water levels at different rate (mean rate 0.173 m/y) whereas three lakes unveiled decreasing trend (mean rate −0.056 m/y). Out of five freshwater lakes, four lakes show an increasing trend of their level (mean rate 0.084 m/y) whereas comparatively six salt lakes (out of seven salt lakes) exhibited ∼3 times higher mean rate of lake level increase (0.233 m/y). These observed lake level rise can be attributed to the increased melt runoffs (i.e., seasonal snow and glacier melts) owing to the enhanced mean annual and seasonal air temperature during past decade in north-western (NW) Himalaya. Further, varied behaviours of lake level rises in inter- and intra-basins suggest that the local climatic fluctuations play prominent role along with regional and global climate in complex geographical system of NW Himalaya.

  18. Ontogenic development of spermatids during spermiogenesis in the high altitude bunchgrass lizard (Sceloporus bicanthalis).

    Science.gov (United States)

    Rheubert, Justin; Touzinsky, Katherine; Hernández-Gallegos, Oswaldo; Granados-González, Gisela; Gribbins, Kevin

    2012-04-01

    The body of ultrastructural data on spermatid characters during spermiogenesis continues to grow in reptiles, but is still relatively limited within the squamates. This study focuses on the ontogenic events of spermiogenesis within a viviparous and continually spermatogenic lizard, from high altitude in Mexico. Between the months of June and August, testicular tissues were collected from eight spermatogenically active bunchgrass lizards (Sceloporus bicanthalis) from Nevado de Toluca, México. The testicular tissues were processed for transmission electron microscopy and analyzed to access the ultrastructural differences between spermatid generations during spermiogenesis. Interestingly, few differences exist between S. bicanthalis spermiogenesis when compared with what has been described for other saurian squamates. Degrading and coiling membrane structures similar to myelin figures were visible within the developing acrosome that are likely remnants from Golgi body vesicles. During spermiogenesis, an electron lucent area between the subacrosomal space and the acrosomal medulla was observed, which has been observed in other squamates but not accurately described. Thus, we elect to term this region the acrosomal lucent ridge. This study furthers the existing knowledge of spermatid development in squamates, which could be useful in future work on the reproductive systems in high altitude viviparous lizard species.

  19. Genotyping the High Altitude Mestizo Ecuadorian Population Affected with Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Andrés López-Cortés

    2017-01-01

    Full Text Available Prostate cancer (PC is the second most commonly diagnosed type of cancer in males with 1,114,072 new cases in 2015. The MTHFR enzyme acts in the folate metabolism, which is essential in methylation and synthesis of nucleic acids. MTHFR C677T alters homocysteine levels and folate assimilation associated with DNA damage. Androgens play essential roles in prostate growth. The SRD5A2 enzyme metabolizes testosterone and the V89L polymorphism reduces in vivo SRD5A2 activity. The androgen receptor gene codes for a three-domain protein that contains two polymorphic trinucleotide repeats (CAG, GGC. Therefore, it is essential to know how PC risk is associated with clinical features and polymorphisms in high altitude Ecuadorian mestizo populations. We analyzed 480 healthy and 326 affected men from our three retrospective case-control studies. We found significant association between MTHFR C/T (odds ratio [OR] = 2.2; P=0.009, MTHFR C/T+T/T (OR = 2.22; P=0.009, and PC. The SRD5A2 A49T substitution was associated with higher pTNM stage (OR = 2.88; P=0.039 and elevated Gleason grade (OR = 3.15; P=0.004. Additionally, patients with ≤21 CAG repeats have an increased risk of developing PC (OR = 2.99; P<0.001. In conclusion, genotype polymorphism studies are important to characterize genetic variations in high altitude mestizo populations.

  20. Effect of Air Pollution, Contamination and High Altitude on Bronchial Asthma

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    Nesriene El margoushy*, Mohamad El Nashar**, Hatem Khairy*, Nihad El Nashar*, Hala Mohamad

    2013-01-01

    Full Text Available Epidemiological studies have shown that the prevalence of asthma has risen dramatically worldwide and evidence suggests that environmental factors have an important role in the etiology of the disease. Most respiratory diseases are caused by airborne agents. Our lungs are uniquely vulnerable to contamination from the air we breathe. Air pollution exposure is associated with increased asthma and allergy morbidity and is a suspected contributor to the increasing prevalence of allergic conditions. Observational studies continue to strengthen the association between air pollution and allergic respiratory disease. The effects of air pollution should be viewed in two different groups: healthy people and people with chronic heart or lung disease. Although the fundamental causes of asthma are not completely understood, the strongest risk factors for developing asthma are inhaled asthma triggers. These include: indoor allergens (for example house dust mites in bedding, carpets and stuffed furniture, pollution and pet dander, outdoor allergens (such as pollens and moulds, tobacco smoke and chemical irritants in the workplace. Other triggers can include cold air, extreme emotional arousal such as anger or fear, and physical exercise. Even certain medications can trigger asthma such as aspirin and other non-steroid anti-inflammatory drugs, and beta-blockers. Urbanization has also been associated with an increase in asthma; however the exact nature of this relationship is unclear. Medication is not the only way to control asthma. It is also important to avoid asthma triggers - stimuli that irritate and inflame the airways. Prevalence of asthma is generally low within the Middle East, although high rates have been recorded in the Kingdom of Saudi Arabia, Kuwait, Lebanon, and Israel. The prevalence of asthma and asthma-related symptoms is high among 16- to 18-year-old adolescents in Saudi Arabia, and the symptoms are more common in boys than in girls

  1. Fatalities in high altitude mountaineering: a review of quantitative risk estimates.

    Science.gov (United States)

    Weinbruch, Stephan; Nordby, Karl-Christian

    2013-12-01

    Quantitative estimates for mortality in high altitude mountaineering are reviewed. Special emphasis is placed on the heterogeneity of the risk estimates and on confounding. Crude estimates for mortality are on the order of 1/1000 to 40/1000 persons above base camp, for both expedition members and high altitude porters. High altitude porters have mostly a lower risk than expedition members (risk ratio for all Nepalese peaks requiring an expedition permit: 0.73; 95 % confidence interval 0.59-0.89). The summit bid is generally the most dangerous part of an expedition for members, whereas most high altitude porters die during route preparation. On 8000 m peaks, the mortality during descent from summit varies between 4/1000 and 134/1000 summiteers (members plus porters). The risk estimates are confounded by human and environmental factors. Information on confounding by gender and age is contradictory and requires further work. There are indications for safety segregation of men and women, with women being more risk averse than men. Citizenship appears to be a significant confounder. Prior high altitude mountaineering experience in Nepal has no protective effect. Commercial expeditions in the Nepalese Himalayas have a lower mortality than traditional expeditions, though after controlling for confounding, the difference is not statistically significant. The overall mortality is increasing with increasing peak altitude for expedition members but not for high altitude porters. In the Nepalese Himalayas and in Alaska, a significant decrease of mortality with calendar year was observed. A few suggestions for further work are made at the end of the article.

  2. High Altitude Infrasound Measurements using Balloon-Borne Arrays

    Science.gov (United States)

    Bowman, D. C.; Johnson, C. S.; Gupta, R. A.; Anderson, J.; Lees, J. M.; Drob, D. P.; Phillips, D.

    2015-12-01

    For the last fifty years, almost all infrasound sensors have been located on the Earth's surface. A few experiments consisting of microphones on poles and tethered aerostats comprise the remainder. Such surface and near-surface arrays likely do not capture the full diversity of acoustic signals in the atmosphere. Here, we describe results from a balloon mounted infrasound array that reached altitudes of up to 38 km (the middle stratosphere). The balloon drifted at the ambient wind speed, resulting in a near total reduction in wind noise. Signals consistent with tropospheric turbulence were detected. A spectral peak in the ocean microbarom range (0.12 - 0.35 Hz) was present on balloon-mounted sensors but not on static infrasound stations near the flight path. A strong 18 Hz signal, possibly related to building ventilation systems, was observed in the stratosphere. A wide variety of other narrow band acoustic signals of uncertain provenance were present throughout the flight, but were absent in simultaneous recordings from nearby ground stations. Similar phenomena were present in spectrograms from the last balloon infrasound campaign in the 1960s. Our results suggest that the infrasonic wave field in the stratosphere is very different from that which is readily detectable on surface stations. This has implications for modeling acoustic energy transfer between the lower and upper atmosphere as well as the detection of novel acoustic signals that never reach the ground. Our work provides valuable constraints on a proposed mission to detect earthquakes on Venus using balloon-borne infrasound sensors.

  3. Local adaptation with high gene flow: temperature parameters drive adaptation to altitude in the common frog (Rana temporaria).

    Science.gov (United States)

    Muir, A P; Biek, R; Thomas, R; Mable, B K

    2014-02-01

    Both environmental and genetic influences can result in phenotypic variation. Quantifying the relative contributions of local adaptation and phenotypic plasticity to phenotypes is key to understanding the effect of environmental variation on populations. Identifying the selective pressures that drive divergence is an important, but often lacking, next step. High gene flow between high- and low-altitude common frog (Rana temporaria) breeding sites has previously been demonstrated in Scotland. The aim of this study was to assess whether local adaptation occurs in the face of high gene flow and to identify potential environmental selection pressures that drive adaptation. Phenotypic variation in larval traits was quantified in R. temporaria from paired high- and low-altitude sites using three common temperature treatments. Local adaptation was assessed using Q(ST)-F(ST) analyses, and quantitative phenotypic divergence was related to environmental parameters using Mantel tests. Although evidence of local adaptation was found for all traits measured, only variation in larval period and growth rate was consistent with adaptation to altitude. Moreover, this was only evident in the three mountains with the highest high-altitude sites. This variation was correlated with mean summer and winter temperatures, suggesting that temperature parameters are potentially strong selective pressures maintaining local adaptation, despite high gene flow.

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

    Directory of Open Access Journals (Sweden)

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

    2014-09-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  6. The Expression Plasticity of Hypoxia Related Genes in High-Altitude and Plains Nanorana parkeri Populations

    Institute of Scientific and Technical Information of China (English)

    Qiong ZHANG; Xingzhi HAN; Robert H S KRAUS; Le YANG; Liqing FAN; Yinzi YE; Yi TAO

    2016-01-01

    For species that have a broad geographic distribution, adaptive variation may be attributable to gene expression plasticity. Nanorana parkeri is an anuran endemic to the southern Tibetan Plateau where it has an extensive altitudinal range (2850 to 5100 m asl). Low oxygen concentration is one of the main environmental characteristics of the Tibetan Plateau. Hypoxia-inducible factor α subunits (HIF-1α and HIF-2α, encoded by Endothelial PAS domain protein 1 (EPAS1)) and associated genes (e.g., vascular endothelial growth factor (VEGF) and Erythropoietin (EPO)) play crucial roles in maintaining oxygen homeostasis. In this study, we compared the expression of HIF-1A, VEGF, EPAS1 and EPO mRNA between two populations of N. parkeri: one population inhabiting the native high altitudes, and the second living in, and being acclimated to, the lower plains (70 m asl). The expression of HIF-1A, VEGF and EPAS1 mRNA in the high altitude population were significantly higher than in the acclimated population, whereas there was no significant difference for EPO between two groups. Our results indicated that gene expression plasticity may make significant contributions to local adaptation of species that have broad altitudinal distributions. In addition, we deepen our understanding of the adaptive potential of this species by evaluating the experiments in the scope of its evolutionary history.

  7. MRI evidence: acute mountain sickness is not associated with cerebral edema formation during simulated high altitude.

    Science.gov (United States)

    Mairer, Klemens; Göbel, Markus; Defrancesco, Michaela; Wille, Maria; Messner, Hubert; Loizides, Alexander; Schocke, Michael; Burtscher, Martin

    2012-01-01

    Acute mountain sickness (AMS) is a common condition among non-acclimatized individuals ascending to high altitude. However, the underlying mechanisms causing the symptoms of AMS are still unknown. It has been suggested that AMS is a mild form of high-altitude cerebral edema both sharing a common pathophysiological mechanism. We hypothesized that brain swelling and consequently AMS development is more pronounced when subjects exercise in hypoxia compared to resting conditions. Twenty males were studied before and after an eight hour passive (PHE) and active (plus exercise) hypoxic exposure (AHE) (F(i)O(2) = 11.0%, P(i)O(2)∼80 mmHg). Cerebral edema formation was investigated with a 1.5 Tesla magnetic resonance scanner and analyzed by voxel based morphometry (VBM), AMS was assessed using the Lake Louise Score. During PHE and AHE AMS was diagnosed in 50% and 70% of participants, respectively (p>0.05). While PHE slightly increased gray and white matter volume and the apparent diffusion coefficient, these changes were clearly more pronounced during AHE but were unrelated to AMS. In conclusion, our findings indicate that rest and especially exercise in normobaric hypoxia are associated with accumulation of water in the extracellular space, however independent of AMS development. Thus, it is suggested that AMS and HACE do not share a common pathophysiological mechanism.

  8. Body composition in air and road inductees at high altitude during the initial days of acclimatization

    Science.gov (United States)

    Ray, U. S.; Selvamurthy, W.

    This study assesses body composition changes and their time course during the initial days of acclimatization to high altitude (HA). Comparisons were made between gradual and acute induction to HA using 60 male lowlander volunteers (24-28 years of age) divided into two equal groups for inducting them to HA. Thirty subjects were air-lifted from sea level (SL) to 3500 m HA in 1 h. These subjects were air inductees (AI). The other 30 subjects were transported in 4 days by road to the same location at 3500 m. These were road inductees (RI). After remaining for 15 days at 3500 m both groups were inducted to 4200 m by road. All the subjects could not reach the various altitudes at the same time due to logistical problems. Ultimately, data for each altitude (SL, 3500 m and 4200 m) were available for only 26 RI subjects and 10 AI subjects. Skinfold thickness (SKF) measurements for the subscapular, thigh, triceps, biceps, juxtanipple, umbilicus, suprailiac and calf regions were taken in order to calculate fat percentages. Measurements were taken at SL and on days 1 and 9 at both 3500 m and 4200 m. On day 1 at 3500 m, RI showed a significant fall in body weight (BW) with respect to SL but AI maintained it. On subsequent days at HA both groups showed a significant fall in BW and lean body mass but not in percentage fat. SKF in the biceps and triceps regions decreased significantly but in the umbilicus and suprailiac regions it significantly increased at HA in both groups. Body composition, along with other parameters, is discussed determining the acclimatization schedule for sojourners at HA. Possibly, translocation of body fat takes place from the periphery to deep body fat depots in the core/main trunk due to the cold at HA.

  9. Cone structure and focusing of VLF and LF electromagnetic waves at high altitudes in the ionosphere

    Science.gov (United States)

    Alpert, Ya. L.; Green, J. L.

    1994-01-01

    The frequency and angle dependencies of the electric field radiated by an electric dipole E = E(sub 0) cos omega(t) are studied through numerical calculations of absolute value of E in the VLF and LF frequency bands where F is less than or equal 0.02 to 0.05 f(sub b) in a model ionosphere over an altitude region of 800-6000 km where the wave frequency and electron gyrofrequency varies between F approximately 4-500 kHz and f(sub b) is approximately equal (1.1 to 0.2) MHz respectively. It is found that the amplitudes of the electric field have large maxima in four regions: close to the direction of the Earth magnetic field line B(sub 0) (it is called the axis field E(sub 0), in the Storey E(sub St), reversed Storey E(sub RevSt), and resonance E(sub Res) cones. The maximal values of E(sub 0), E(sub Res), and E(sub RevSt) are the most pronounced close to the lower hybrid frequency, F approximately F(sub L). The flux of the electric field is concentrated in very narrow regions, with the apex angles of the cones Delta-B is approximately (0.1-1) deg. The enhancement and focusing of the electric field increases with altitude starting at Z greater than 800 km. At Z greater than or equal to 1000 up to 6000 km, the relative value of absolute value of E, in comparison with its value at Z = 800 km is about (10(exp 2) to 10(exp 4)) times larger. Thus the flux of VLF and LF electromagnetic waves generated at high altitudes in the Earth's ionosphere are trapped into very narrow conical beams similar to laser beams.

  10. Cone structure and focusing of VLF and LF electromagnetic waves at high altitudes in the ionosphere

    Science.gov (United States)

    Alpert, Ya. L.; Green, J. L.

    1994-01-01

    The frequency and angle dependencies of the electric field radiated by an electric dipole E = E(sub 0) cos omega(t) are studied through numerical calculations of absolute value of E in the VLF and LF frequency bands where F is less than or equal 0.02 to 0.05 f(sub b) in a model ionosphere over an altitude region of 800-6000 km where the wave frequency and electron gyrofrequency varies between F approximately 4-500 kHz and f(sub b) is approximately equal (1.1 to 0.2) MHz respectively. It is found that the amplitudes of the electric field have large maxima in four regions: close to the direction of the Earth magnetic field line B(sub 0) (it is called the axis field E(sub 0), in the Storey E(sub St), reversed Storey E(sub RevSt), and resonance E(sub Res) cones. The maximal values of E(sub 0), E(sub Res), and E(sub RevSt) are the most pronounced close to the lower hybrid frequency, F approximately F(sub L). The flux of the electric field is concentrated in very narrow regions, with the apex angles of the cones Delta-B is approximately (0.1-1) deg. The enhancement and focusing of the electric field increases with altitude starting at Z greater than 800 km. At Z greater than or equal to 1000 up to 6000 km, the relative value of absolute value of E, in comparison with its value at Z = 800 km is about (10(exp 2) to 10(exp 4)) times larger. Thus the flux of VLF and LF electromagnetic waves generated at high altitudes in the Earth's ionosphere are trapped into very narrow conical beams similar to laser beams.

  11. Biogas production from llama and cow manure at high altitude

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Rene; Villca, Saul [IIDEPROQ, UMSA, Plaza del Obelisco 1175, La Paz (Bolivia); Liden, Gunnar [Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund (Sweden)

    2006-01-15

    Methane production from llama and cow manures from the Bolivian high plateau (The 'Altiplano') was studied using a parallel reactor set-up consisting of 10 lab-scale biogasifiers. The effects of pressure (495 and 760mmHg), temperature (11 and 35 deg C), hydraulic retention time (20 and 50 days), and manure content in the slurry (10%, 20% and 50%) were evaluated with respect to productivity and methane yields based on two {sup 4-1} fractional factorial designs with 8 treatments for each kind of manure. The reactors were operated semi-continuously with daily manure feeding for periods between 50 and 100 days. Temperature was the main factor effect found, and the hydraulic retention time and the manure content in feed were also found significant whereas the effect of pressure was not significant in the range studied. The methane yield obtained with cow manure at 11 deg C was between 6.4 and 33.61 CH{sub 4} kg{sup -1} VS (volatile solids added) whereas at 35 deg C the methane yield was between 49.6 and 131.31 CH{sub 4} kg{sup -1} VS. The methane yield from llama manure was somewhat lower than for cow manure (between 3.3 and 19.31 CH{sub 4} kg{sup -1} VS at 11 deg C and between 35.6 and 84.11 CH{sub 4} kg{sup -1} VS at 35 deg C, respectively). However, overall llama manure was found to be the best raw material of the two for biogas production, due to its high content of volatile solid - higher than has been previously reported for most manures - and also its high nitrogen and phosphorous content. (author)

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

    Science.gov (United States)

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

    2017-01-01

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

  13. Ozone Exposure System Designed and Used to High-Altitude Airship Materials

    Science.gov (United States)

    Miller, Sharon K.

    2005-01-01

    High-altitude airships can receive high doses of ozone over short mission durations. For example, in 1 year at an altitude of 70,000 ft, the ozone fluence (number arriving per unit area) can be as high as 1.2 1024 molecules/sq cm. Ozone exposure at these levels can embrittle materials or change the performance of solar cells. It is important to expose components and materials to the expected ozone dosage to determine if the ozone exposure could cause any mission-critical failures.

  14. Polymorphisms of the tissue inhibitor of metalloproteinase 3 gene are associated with resistance to high-altitude pulmonary edema (HAPE in a Japanese population: a case control study using polymorphic microsatellite markers.

    Directory of Open Access Journals (Sweden)

    Nobumitsu Kobayashi

    Full Text Available INTRODUCTION: High-altitude pulmonary edema (HAPE is a hypoxia-induced, life-threatening, high permeability type of edema attributable to pulmonary capillary stress failure. Genome-wide association analysis is necessary to better understand how genetics influence the outcome of HAPE. MATERIALS AND METHODS: DNA samples were collected from 53 subjects susceptible to HAPE (HAPE-s and 67 elite Alpinists resistant to HAPE (HAPE-r. The genome scan was carried out using 400 polymorphic microsatellite markers throughout the whole genome in all subjects. In addition, six single nucleotide polymorphisms (SNPs of the gene encoding the tissue inhibitor of metalloproteinase 3 (TIMP3 were genotyped by Taqman® SNP Genotyping Assays. RESULTS: The results were analyzed using case-control comparisons. Whole genome scanning revealed that allele frequencies in nine markers were statistically different between HAPE-s and HAPE-r subjects. The SNP genotyping of the TIMP3 gene revealed that the derived allele C of rs130293 was associated with resistance to HAPE [odds ratio (OR = 0.21, P = 0.0012 and recessive inheritance of the phenotype of HAPE-s (P = 0.0012. A haplotype CAC carrying allele C of rs130293 was associated with resistance to HAPE. DISCUSSION: This genome-wide association study revealed several novel candidate genes associated with susceptibility or resistance to HAPE in a Japanese population. Among those, the minor allele C of rs130293 (C/T in the TIMP3 gene was linked to resistance to HAPE; while, the ancestral allele T was associated with susceptibility to HAPE.

  15. A strategy for oxygen conditioning at high altitude: comparison with air conditioning.

    Science.gov (United States)

    West, John B

    2015-09-15

    Large numbers of people live or work at high altitude, and many visit to trek or ski. The inevitable hypoxia impairs physical working capacity, and at higher altitudes there is also cognitive impairment. Twenty years ago oxygen enrichment of room air was introduced to reduce the hypoxia, and this is now used in dormitories, hotels, mines, and telescopes. However, recent advances in technology now allow large amounts of oxygen to be obtained from air or cryogenic oxygen sources. As a result it is now feasible to oxygenate large buildings and even institutions such as hospitals. An analogy can be drawn between air conditioning that has improved the living and working conditions of millions of people who live in hot climates and oxygen conditioning that can do the same at high altitude. Oxygen conditioning is similar to air conditioning except that instead of cooling the air, the oxygen concentration is raised, thus reducing the equivalent altitude. Oxygen conditioning on a large scale could transform living and working conditions at high altitude, where it could be valuable in homes, hospitals, schools, dormitories, company headquarters, banks, and legislative settings. Copyright © 2015 the American Physiological Society.

  16. Solar Cell Short Circuit Current Errors and Uncertainties During High Altitude Calibrations

    Science.gov (United States)

    Snyder, David D.

    2012-01-01

    High altitude balloon based facilities can make solar cell calibration measurements above 99.5% of the atmosphere to use for adjusting laboratory solar simulators. While close to on-orbit illumination, the small attenuation to the spectra may result in under measurements of solar cell parameters. Variations of stratospheric weather, may produce flight-to-flight measurement variations. To support the NSCAP effort, this work quantifies some of the effects on solar cell short circuit current (Isc) measurements on triple junction sub-cells. This work looks at several types of high altitude methods, direct high altitude meas urements near 120 kft, and lower stratospheric Langley plots from aircraft. It also looks at Langley extrapolation from altitudes above most of the ozone, for potential small balloon payloads. A convolution of the sub-cell spectral response with the standard solar spectrum modified by several absorption processes is used to determine the relative change from AMO, lscllsc(AMO). Rayleigh scattering, molecular scatterin g from uniformly mixed gases, Ozone, and water vapor, are included in this analysis. A range of atmosph eric pressures are examined, from 0. 05 to 0.25 Atm to cover the range of atmospheric altitudes where solar cell calibrations a reperformed. Generally these errors and uncertainties are less than 0.2%

  17. [Physical performance of older adults living in rural areas at sea level and at high altitude in Peru].

    Science.gov (United States)

    Estela-Ayamamani, David; Espinoza-Figueroa, Jossué; Columbus-Morales, Mauricio; Runzer-Colmenares, Fernando; Parodi, José F; Mayta-Tristán, Percy

    2015-01-01

    Living at high altitudes requires the inhabitants to adapt biologically and socially to the environment. The objective of this study was to determine the difference in physical performance (PP) in rural populations at sea level and at high altitude. A cross-sectional study was conducted in rural communities in Ancash, Peru, located at 3.345 meters above sea level (m.a.s.l.) and also in communities located in coastal areas at 6m.a.s.l. PP was measured by the Short Physical Performance Battery (SPPB) and other associated factors. Adjusted prevalence ratios (aPR) were calculated. A total of 130 older adults were assessed in the high altitude communities and 129 on the coast. The median age was 71.4 years, and 55.6% were female. Low physical performance (SPPB ≤ 6) was 10.0% at high altitude and 19.4% on the coast (p<0.05). Factors associated with low physical performance were residing at the coast (aPR: 2.10, 95% CI 1.02 to 4.33), self-reported poor health (aPR: 2.48, 95% CI 1.21 -5.08), hypertension (aPR: 1.73, 95% CI 1.01 to 2.98), and age (aPR: 1.04, 95% CI 1.01 to 1.07), while being a farmer (aPR: 0.49, 95% CI 0.25 to 0.97), and being independent (aPR: 0.37, 95% CI 0,20-, 072) were found to be protective factors. It was also found that the inhabitants of the coast have a mean of 0.86 points lower total SPPB than the high altitude ones (p=0.004). There is an association between altitude of residence and PP in older adults. The prevalence of a low PP in older adults in rural areas at sea level is twice as high compared to those living in high altitude rural communities. Copyright © 2014 SEGG. Published by Elsevier Espana. All rights reserved.

  18. Pruning management of Chardonnay grapevines at high altitude in Brazilian southeast

    Directory of Open Access Journals (Sweden)

    Tania dos Reis Mendonça

    2016-03-01

    Full Text Available ABSTRACT The agronomical responses of Chardonnay, a variety indicated for sparkling wine production, is influenced by the vineyard management and the edaphoclimatic conditions of the region. The objective of this study was to evaluate the effects of two pruning types (Royat and double Guyot on vegetative and reproductive development of Chardonnay vine growing at high altitude in the Brazilian southeastern region. The experiment was carried out in a commercial vineyard located at 1,280 m of altitude in Divinolândia, São Paulo State, Brazil. The Chardonnay vines (clone 96, grafted onto 1103 Paulsen rootstock and trained in a vertical shoot positioning trellis system, were assessed. Vegetative vigor, bud fruitfulness, production and physicochemical composition of grapes were evaluated during 2014 and 2015 growing seasons. The Royat pruning induced higher vegetative vigor and increased the bud fruitfulness, the cluster number and the productivity of Chardonnay vine when compared to Guyot pruning. Even though the increase on yield was observed, there was no effect of pruning type on grape final quality. Therefore, the choice of pruning method in function of variety genetic characteristics and their interaction with environment can optimize the vineyard profitability. In the Brazilian southeast, the Royat system is the most suitable one to grow Chardonnay for sparkling wines production.

  19. An Examination of Corrections for High Altitude, High Speed Airborne Gravimetry

    Science.gov (United States)

    Preaux, S. A.; Diehl, T. M.; Childers, V. A.

    2009-12-01

    Standard corrections for airborne gravimetry are optimized for low altitude, low speed surveys. They are shown to have multi-mgal errors at the high altitude and high speed of the surveys for the GRAV-D project. Higher order methods for computing the Eötvös, free air and off-level corrections are investigated. The first and second order approximations for the Eötvös correction from Harlan (1968) have differences up to 6 mgal, depending on latitude, and include assumptions about Earth shape that are undesirable in a geodetic application. Similarly, first and second order approximations for the free air correction (Hackney and Featherstone 2003) differ by up to 20 mgal and contain assumptions about Earth shape. Including more sophisticated downward continuation when incorporating data into a geoid model may be preferable to applying a free air correction. Finally, an exact analytical method of correcting for aircraft motion and orientation is proposed which takes advantage of the GPS reference system to avoid Earth shape assumptions, eliminate approximations and yield vector gravity.

  20. Nighttime chemistry at a high altitude site above Hong Kong

    Science.gov (United States)

    Brown, Steven S.; Dubé, William P.; Tham, Yee Jun; Zha, Qiaozhi; Xue, Likun; Poon, Steven; Wang, Zhe; Blake, Donald R.; Tsui, Wilson; Parrish, David D.; Wang, Tao

    2016-03-01

    Nighttime reactions of nitrogen oxides influence ozone, volatile organic compounds, and aerosol and are thus important to the understanding of regional air quality. Despite large emissions and rapid recent growth of nitrogen oxide concentrations, there are few studies of nighttime chemistry in China. Here we present measurements of nighttime nitrogen oxides, NO3 and N2O5, from a coastal mountaintop site in Hong Kong adjacent to the megacities of the Pearl River Delta region. This is the first study of nighttime chemistry from a site within the residual layer in China. Key findings include the following. First, highly concentrated urban NOx outflow from the Pearl River Delta region was sampled infrequently at night, with N2O5 mixing ratios up to 8 ppbv (1 min average) or 12 ppbv (1 s average) in nighttime aged air masses. Second, the average N2O5 uptake coefficient was determined from a best fit to the available steady state lifetime data as γ(N2O5) = 0.014 ± 0.007. Although this determination is uncertain due to the difficulty of separating N2O5 losses from those of NO3, this value is in the range of previous residual layer determinations of N2O5 uptake coefficients in polluted air in North America. Third, there was a significant contribution of biogenic hydrocarbons to NO3 loss inferred from canister samples taken during daytime. Finally, daytime N2O5 mixing ratios were in accord with their predicted photochemical steady state. Heterogeneous uptake of N2O5 in fog is determined to be an important production mechanism for soluble nitrate, even during daytime.

  1. NGC 1252: a high altitude, metal poor open cluster remnant

    CERN Document Server

    Marcos, R de la Fuente; Bidin, C Moni; Carraro, G; Costa, E

    2013-01-01

    If stars form in clusters but most stars belong to the field, understanding the details of the transition from the former to the latter is imperative to explain the observational properties of the field. Aging open clusters are one of the sources of field stars. The disruption rate of open clusters slows down with age but, as an object gets older, the distinction between the remaining cluster or open cluster remnant (OCR) and the surrounding field becomes less and less obvious. As a result, finding good OCR candidates or confirming the OCR nature of some of the best candidates still remain elusive. One of these objects is NGC 1252, a scattered group of about 20 stars in Horologium. Here we use new wide-field photometry in the UBVI pass-bands, proper motions from the Yale/San Juan SPM 4.0 catalogue, and high resolution spectroscopy concurrently with results from N-body simulations to decypher NGC 1252's enigmatic character. Spectroscopy shows that most of the brightest stars in the studied area are chemically,...

  2. Angus calves born and raised at high altitude adapt to hypobaric hypoxia by increasing alveolar ventilation rate but not hematocrit.

    Science.gov (United States)

    Gulick, A K; Garry, F B; Holt, T N; Retallick-Trennepohl, K; Enns, R M; Thomas, M G; Neary, J M

    2016-10-01

    The objective of this study was to evaluate the effect of altitude on arterial blood-gases and hematocrit in Angus-based calves. It was hypothesized that alveolar ventilation rate, as indicated by arterial pCO, would increase with altitude but hematocrit would not. Five Angus-based herds ( = 30 to 80 per cohort) located at 105 m, 1,470 m, 2,010 m, 2,170 m, and 2,730 m above sea level were enrolled in this prospective cohort study. A portable analyzer measured blood-gas tensions in coccygeal arterial blood. Calves at 1,470 m, 2,170 m, and 2,730 m were sampled twice, at approximately 4 mo and 7 mo of age. Calves at 105 m and 2,010 m were sampled once, at 7 or 4 mo of age, respectively. Linear regression analyses were used to determine the fixed effect of herd (a proxy for altitude) on the 4 outcome variables pCO, pO, pH, and hematocrit, while controlling for age and sex. As hypothesized, alveolar ventilation rate increased with altitude ( < 0.001). Hematocrit, however, did not show a clear association with altitude except for an increase from 105 m to ≥ 1,470 m ( < 0.001). Arterial pO decreased significantly with increasing altitude in calves at 4 mo and 7 mo of age ( < 0.001). The adjusted mean values of the 4 variables studied were similar at 4 and 7 mo of age for all of the herds studied. This indicates that suckling calves show minimal respiratory or erythrocytic adaptation to hypoxemia and hypocapnia with increasing age, regardless of altitude. We propose that the lack of an erythrocytic response in hypoxemic calves born and raised at high altitude prevents a deleterious increase in viscous resistance and, consequently, pulmonary arterial pressure. This physiological response, or lack thereof, may be a survival adaptation in a species predisposed to hypoxia-induced pulmonary hypertension.

  3. De-adaptation change in cardiac function of laborers engaged in physical labor at high altitude after returning to lower altitude

    Directory of Open Access Journals (Sweden)

    En-zhi FENG

    2012-09-01

    Full Text Available Objective To assess the effects of physical labor on cardiac function of laborers at high altitude and changes in cardiac function after returning to lower altitude. Methods According to symptomatic scores on Chinese acute high altitude reaction (AHAR, 96 male officers and soldiers, who rapidly entered high altitude areas (3700m altitude,and engaged in heavy physical work for 50 days, were be scored and graded. Levels of creatine kinase isoenzymes -MB (CK-MB and lactic dehydrogenase isoenzyme -1 (LDH-1 in the serum, Tei index, left ventricular ejection fraction (LVEF, and left ventricular fractional shortening (LVFS were measured in the 96 servicemen at the 50th day of residing at high altitude, and the 2nd and 15th day after returning to lower altitude (1500m altitude, and the results were compared with that of 50 healthy controls residing at 1500m. Results  Among the 96 male servicemen, 71 developed AHAR, and 24 of them had severe AHAR, 47 mild to moderate AHAR, and the rest 25 had no AHAR. Levels of serum CK-MB, LDH-1 and Tei index were higher in the severe AHAR group than in the mild to moderate AHAR group, higher in the mild to moderate AHAR group than in the no AHAR group and higher in the no AHAR group than in the healthy group. As far as the values of LVEF and LVFS were concerned, the severe AHAR group < mild to moderate AHAR group < no AHAR group < control group. Significant difference was found in these levels between every two successive groups (P < 0.01. Linear correlation analysis showed that levels of CK-MB and LDH-1 of persons staying at 3700m altitude for 50 days were positively correlated with Tei index (r= 0.625, 0.598, respectively, P<0.01, and negatively correlated with LVEF(r=-0.716, -0.658, respectively, P<0.01, and also negatively correlated with LVFS (r=-0.639, -0.727, respectively, P<0.01. Level of serum CK-MB, LDH-1 and Tei index at 3700m altitude for 50 days were significantly higher than those 2

  4. Retrospective study of nursing care adverse events at high altitude area of Lhasa city%拉萨地区护理不良事件回顾性研究

    Institute of Scientific and Technical Information of China (English)

    嘎多; 刘晓琴; 黄萍; 付丽萍; 许玉华

    2016-01-01

    目的:对拉萨地区护理不良事件发生状况、原因进行分析,为拉萨地区护理质量与安全管理提供参考依据。方法对西藏自治区人民医院2013年1月至2014年8月上报的50例护理不良事件分类、分级、原因、发生时间等进行分析。结果50例护理不良事件中构成比居前3位的是管路滑脱13例占26%、压疮7例占14%和烫伤6例占12%;级别构成比分别为隐患事件24例占48%、未造成后果事件18例占36%、不良事件7例占14%和警告事件1例占2%;沟通不良、评估不足、未遵守制度发生原因为35例占70%;7:00-10:59和19:00-22:59两个时段为不良事件高发时段,分别为16例占32%和13例占26%。结论拉萨地区护理不良事件的管理,需要考虑社会、地域特点,可以采取保障制度落实,降低床护比,提高护理人员综合素质等管理措施减少不良事件的发生。%Objective To understand the status and features of nursing care adverse events and to offer scientific basis for improving patient safety management of nursing at high altitude area. Methods Data such as categories, causes, time distribution and other factors of nursing care adverse events were collected from January 2013 to August 2014 in the People′s Hospital of Tibet Autonomous Region were analyzed. Results Over the study period, 50 adverse events were recorded and the most common types were tube emersion(26%,13/50), pressure sores(14%,7/50) and scald(12%,6/50) respectively. The proportions of different severity of adverse events were hidden events (48%,24/50), events without bad consequence(36%,18/50), adverse events(14%,7/50) and warning events(2%,1/50) respectively. The ineffective communication, inadequate assessment, and not abiding by the rules accounted for 70%(35/50) of the causes of adverse events. 7:00-10:59 and 19:00-22:59 period was the high incidence of adverse events, respectively accounted for 32%(16/50) and 26

  5. Proceedings of the Workshop on High Altitude Data Assimilation and Modeling

    Science.gov (United States)

    2015-06-24

    Radar   (OTHR)   applications.       • The   nominal   lifetime   of   existing   operational  DMSP   platforms   is   5...high-­‐yield   conventional   explosives,   underground   nuclear   testing).   High-­‐altitude   data   assimilation   is

  6. Managing High-Altitude Pulmonary Edema with Oxygen Alone: Results of a Randomized Controlled Trial.

    Science.gov (United States)

    Yanamandra, Uday; Nair, Velu; Singh, Surinderpal; Gupta, Amul; Mulajkar, Deepak; Yanamandra, Sushma; Norgais, Konchok; Mukherjee, Ruchira; Singh, Vikrant; Bhattachar, Srinivasa A; Patyal, Sagarika; Grewal, Rajan; Chopra, Bhushan

    2016-12-01

    Yanamandra, Uday, Velu Nair, Surinderpal Singh, Amul Gupta, Deepak Mulajkar, Sushma Yanamandra, Konchok Norgais, Ruchira Mukherjee, Vikrant Singh, Srinivasa A. Bhattachar, Sagarika Patyal, and Rajan Grewal. High-altitude pulmonary edema management: Is anything other than oxygen required? Results of a randomized controlled trial. High Alt Med Biol. 17:294-299, 2016.-Treatment strategies for management of high-altitude pulmonary edema (HAPE) are mainly based on the observational studies with only two randomized controlled trials, thus the practice is very heterogeneous and individualized as per the choice of treating physician. To compare the response to different modalities of therapy in patients with HAPE in a randomized controlled manner. We conducted an open-label, randomized noninferiority trial to compare three modalities of therapy (Therapy 1: supplemental O2 with oral dexamethasone 8 mg q8 hours [n = 42], Therapy 2: supplemental O2 with sustained release oral nifedipine 20 mg q8 hours [n = 41], and Therapy 3: only supplemental O2 [n = 50]). Bed rest was mandated in all patients. The study was conducted in a cohort of previously healthy young lowlander males at an altitude of 3500 m. Baseline characteristics of the patients were comparable in the study arms. Complete response was defined as clinical and radiological resolution of features of HAPE, no oxygen dependency, a normal 6-minute walk test (6MWT) on 2 consecutive days, and normal two-dimensional echocardiography. Results were compared by analysis of variance using SPSS version 16.0. There was no statistical difference in duration of therapy to complete response between the three groups (Therapy 1: 8.1 ± 4.0 days, Therapy 2: 6.7 ± 3.9 days, Therapy 3: 6.8 ± 3.2 days; p = 0.15). There were no deaths in any of the groups. We conclude that oxygen and bed rest alone are adequate therapy for HAPE and that adjuvant pharmacotherapy with either dexamethasone or nifedipine

  7. The High Altitude Water Čerenkov (HAWC) TeV Gamma Ray Observatory

    Science.gov (United States)

    de la Fuente, Eduardo; Oceguera-Becerra, Tomas; García-Torales, Guillermo; García-Luna, José Luis

    The High Altitude Water Čerenkov observatory is a second generation ground based very high-energy γ-ray detector under construction in Sierra Negra, Puebla, México at an altitude of 4,100m. Higher altitude, improved design and a larger physical size used to reject cosmic ray background, make HAWC 10-20 times more sensitive than its predecessor Milagro. HAWC's large field of view (˜2sr) and over 90% duty cycle make it ideal to search for several types of TeV astronomical γ-ray sources, diffuse emission, cosmic anisotropy, and transients. Details and status of HAWC at date, and a galactic star formation application are here presented.

  8. The effect of temperature variation on biomethanation at high altitude.

    Science.gov (United States)

    Alvarez, René; Lidén, Gunnar

    2008-10-01

    The aim of the current study was to examine effects of daily temperature variations on the performance of anaerobic digestion. Forced square-wave temperature variations (between 11 and 25, 15 and 28, and 19 and 32 degrees C) were imposed on a bench-scale digester using a mixture of llama-cow-sheep manure in a semi-continuous process. The volumetric biogas production rate, methane yield, and the volatile solid reductions were compared with the results obtained from anaerobic digestion (AD) at constant temperatures. The forced cyclic variations of temperature caused large cyclic variations in the rate of gas production and the methane content. As much as 94-97% of the daily biogas was obtained in the 12h half-cycle at high temperature. The values for volumetric biogas production rate and methane yield increased at higher temperatures. The average volumetric biogas production rate for cyclic operation between 11 and 25 degrees C was 0.22Ld(-1)L(-1) with a yield of 0.07m3CH4kg(-1) VS added (VSadd), whereas for operation between 15 and 29 degrees C the volumetric biogas production rate increased by 25% (to 0.27Ld(-1)L(-1) with a yield of 0.08m3CH4kg(-1) VSadd). In the highest temperature region a further increase of 7% in biogas production was found and the methane yield was 0.089m(3)CH(4)kg(-1) VSadd. The employed digester showed an immediate response when the temperature was elevated, which indicates a well-maintained metabolic capacity of the methanogenic bacteria during the period of low temperature. Overall, periodic temperature variations appear to give less decrease in process performance than a priori anticipated.

  9. The Channel Estimation and Modeling in High Altitude Platform Station Wireless Communication Dynamic Network

    Directory of Open Access Journals (Sweden)

    Xiaoyang Liu

    2017-01-01

    Full Text Available In order to analyze the channel estimation performance of near space high altitude platform station (HAPS in wireless communication system, the structure and formation of HAPS are studied in this paper. The traditional Least Squares (LS channel estimation method and Singular Value Decomposition-Linear Minimum Mean-Squared (SVD-LMMS channel estimation method are compared and investigated. A novel channel estimation method and model are proposed. The channel estimation performance of HAPS is studied deeply. The simulation and theoretical analysis results show that the performance of the proposed method is better than the traditional methods. The lower Bit Error Rate (BER and higher Signal Noise Ratio (SNR can be obtained by the proposed method compared with the LS and SVD-LMMS methods.

  10. High-resolution Ceres High Altitude Mapping Orbit atlas derived from Dawn Framing Camera images

    Science.gov (United States)

    Roatsch, Th.; Kersten, E.; Matz, K.-D.; Preusker, F.; Scholten, F.; Jaumann, R.; Raymond, C. A.; Russell, C. T.

    2016-09-01

    The Dawn spacecraft Framing Camera (FC) acquired over 2400 clear filter images of Ceres with a resolution of about 140 m/pixel during the six cycles in the High Altitude Mapping Orbit (HAMO) phase between August 18 and October 21, 2015. We ortho-rectified the images from the first cycle and produced a global, high-resolution, controlled photomosaic of Ceres. This global mosaic is the basis for a high-resolution Ceres atlas that consists of 15 tiles mapped at a scale of 1:750,000. The nomenclature used in this atlas was proposed by the Dawn team and was approved by the International Astronomical Union (IAU). The full atlas is available to the public through the Dawn Geographical Information System (GIS) web page

  11. Cane pruning on Chardonnay grapevine in the high-altitude regions of Southern Brazil

    Directory of Open Access Journals (Sweden)

    Filho José Luiz Marcon

    2016-01-01

    Full Text Available High-altitude regions of southern Brazil, located above 900 m above sea level, the cordon training with spur pruning is widely used because of easier application. In these regions, Chardonnay wine grape shows potential to produce quality wines, however, in commercial vineyards, the training system used has not provided productivities that makes economically viable the cultivation of this variety. Given this, the present study aimed to evaluate the effect of different cane-pruning systems on the vegetative, productive and enological potential of Chardonnay grapevines grown in the high-altitude region of Southern Brazil. The experiment was conducted in a commercial Chardonnay vineyard, located in São Joaquim – Santa Catarina State (28o17 ′39”S and 49∘ 55′56” W, to 1230 m a.s.l during 2015 and 2016 vintages. Chardonnay vines (grafted on 1103 Paulsen were planted in 2010, with a 3.0 m (row × 1.0 m (vine spacing. The treatments consisted of different cane-pruning systems: Cordon spur-pruning (control; Sylvoz; Cazenave; Capovolto; single Guyot and double Guyot. Pruning was performed in August of each year when the buds were in the green tip developmental stage. Data was analyzed by Scott Knott test (p < 0.05 following a randomized block design with four replicates, each consisting of 12 vines per plot. We observed higher yield in the Cazenave and double Guyot training system with three and two more tons of grapes than spur-pruning respectively. The bud fertility was higher in plants trained in double Guyot. Vines spur-pruned showed higher relation of leaf area: production, with values above 100 cm2 g−1 grape at 2016 vintage. Commercial maturity of grapes (soluble solids, acidity and polyphenols did not differ among training systems studied. The results suggest that cane-pruning systems could be an alternative to increase production efficiency of Chardonnay in high-altitude region of southern Brazil.

  12. PHYTOCHEMICAL AND PROTEOMIC ANALYSIS OF A HIGH ALTITUDE MEDICINAL MUSHROOM CORDYCEPS SINENSIS

    Directory of Open Access Journals (Sweden)

    Rakhee

    2016-09-01

    Full Text Available Cordyceps sinensis (C. sinensis is well established as a traditional Chinese medicine (TCM that has been valued as a health food for centuries. It is an entomopathogenic fungus in Ascomycetes that naturally occurs at high altitude in Himalayan region and has received considerable attention due to the abundance of various biologically active compounds. Despite having reported health benefits and economic importance, qualitative phytochemical analysis, proximate composition and proteome study of Indian isolates of C. sinensis grown at high altitude remains untapped. In the present study, qualitative phytochemical analysis was carried on powdered whole body of C. sinensis (CSWb and its aqueous extract (CSAq prepared by accelerated solvent extraction technique which indicated the presence of several bioactive constituents such as alkaloids, amino acids and proteins, carbohydrates, flavonoids and phenols, gums, mucilages and saponins. We evaluated chemical composition of the Indian Himalayan medicinal mushroom C. sinensis in terms of its carbohydrate (55.68% content, crude fiber (6.40%, fat (1.80%, moisture (7.18%, protein (21.46% and total ash (7.48%. Furthermore, soluble protein identification of both CSWb and CSAq by SDS-PAGE followed by MALDI-TOF-TOF analysis revealed the presence of various types of most abundant proteins such as P-type II A ATPase, TE1b [Blumeriagraminis f. sp. hordei], Chitin synthase Chs [Penicilliummarneffei ATCC 18224], Serine/threonine-protein kinase CLA4, DEHA2C06820p [Debaryomyceshansenii CBS767], YALI0E29887p [Yarrowialipolytica] etc. In conclusion, the present study provides a comprehensive qualitative phytochemical analysis, proximate composition and proteome study on Indian isolate of C. sinensis which could endorse its use as a functional food.

  13. Over-starvation aggravates intestinal injury and promotes bacterial and endotoxin translocation under high-altitude hypoxic environment

    Institute of Scientific and Technical Information of China (English)

    Qi-Quan Zhou; Ding-Zhou Yang; Yong-Jun Luo; Su-Zhi Li; Fu-Yu Liu; Guan-Song Wang

    2011-01-01

    AIM: To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment. METHODS: Sprague-Dawley rats were exposed to hypobaric hypoxia at a simulated altitude of 7000 m for 72 h. Lanthanum nitrate was used as a tracer to detect intestinal injury. Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Serum levels of diamino oxidase (DAO), malondialdehyde (MDA), glutamine (Gln), superoxide dismutase (SOD) and endotoxin were measured in intestinal mucosa. Bacterial translocation was detected in blood culture and intestinal homogenates. In addition, rats were given Gln intragastrically to observe its protective effect on intestinal injury. RESULTS: Apoptotic epithelial cells, exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells. Lanthanum particles were found in the intercellular space and intracellular compartment. Bacterial translocation to mesenteric lymph nodes (MLN) and spleen was evident. The serum endotoxin, DAO and MDA levels were significantly higher while the serum SOD, DAO and Gln levels were lower in intestine (P < 0.05). The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group (0.47 ± 0.83 vs 2.38 ± 1.45, P < 0.05). The bacterial translocation was found in each organ, especially in MLN and spleen but not in peripheral blood. The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln. CONCLUSION: High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation, which can be treated with Gln.

  14. Tropical deep convective life cycle: Cb-anvil cloud microphysics from high-altitude aircraft observations

    Science.gov (United States)

    Frey, W.; Borrmann, S.; Fierli, F.; Weigel, R.; Mitev, V.; Matthey, R.; Ravegnani, F.; Sitnikov, N. M.; Ulanovsky, A.; Cairo, F.

    2014-12-01

    The case study presented here focuses on the life cycle of clouds in the anvil region of a tropical deep convective system. During the SCOUT-O3 campaign from Darwin, Northern Australia, the Hector storm system has been probed by the Geophysica high-altitude aircraft. Clouds were observed by in situ particle probes, a backscatter sonde, and a miniature lidar. Additionally, aerosol number concentrations have been measured. On 30 November 2005 a double flight took place and Hector was probed throughout its life cycle in its developing, mature, and dissipating stage. The two flights were four hours apart and focused on the anvil region of Hector in altitudes between 10.5 and 18.8 km (i.e. above 350 K potential temperature). Trajectory calculations, satellite imagery, and ozone measurements have been used to ensure that the same cloud air masses have been probed in both flights. The size distributions derived from the measurements show a change not only with increasing altitude but also with the evolution of Hector. Clearly different cloud to aerosol particle ratios as well as varying ice crystal morphology have been found for the different development stages of Hector, indicating different freezing mechanisms. The development phase exhibits the smallest ice particles (up to 300 μm) with a rather uniform morphology. This is indicative for rapid glaciation during Hector's development. Sizes of ice crystals are largest in the mature stage (larger than 1.6 mm) and even exceed those of some continental tropical deep convective clouds, also in their number concentrations. The backscatter properties and particle images show a change in ice crystal shape from the developing phase to rimed and aggregated particles in the mature and dissipating stages; the specific shape of particles in the developing phase cannot be distinguished from the measurements. Although optically thin, the clouds in the dissipating stage have a large vertical extent (roughly 6 km) and persist for at

  15. Higher and colder: The success and failure of boundaries in high altitude and Antarctic research stations.

    Science.gov (United States)

    Heggie, Vanessa

    2016-12-01

    This article offers a series of case studies of field stations and field laboratories based at high altitudes in the Alps, Himalayas and Antarctica, which have been used by Western scientists (largely physiologists and physicists) from circa 1820 to present. It rejects the common frame for work on such spaces that polarizes a set of generalizations about practices undertaken in 'the field' versus 'the laboratory'. Field sites are revealed as places that can be used to highlight common and crucial features of modern experimental science that are exposed by, but not uniquely the properties of, fieldwork. This includes heterogeneity of population and practice, diverse afterlives, the manner in which spaces of science construct individual and group expertise, and the extensive support and funding structures needed for modern scientific work.

  16. Molecular mechanisms regulating oxygen transport and consumption in high altitude and hibernating mammals

    DEFF Research Database (Denmark)

    Revsbech, Inge Grønvall

    2016-01-01

    The aim of this thesis is to broaden the knowledge of molecular mechanisms of adjustment in oxygen (O2) uptake, conduction, delivery and consumption in mammals adapted to extreme conditions. For this end, I have worked with animals living at high altitude as an example of environmental hypoxia......, and hibernating mammals, as an example of closely balanced internal low O2. Studies have had two main focus points. Firstly, I have investigated variations in hemolysate and hemoglobin (Hb) O2 affinity, working to pinpoint whether and how functional changes in intrinsic affinity or cofactor sensitivity of the Hb...... molecule compares to amino acid substitutions in the molecule, i.e., can be characterized as evolved genetic adaptation. Phenotypic acclimatization in Hb- O2 affinity responses involves changes in cofactor to Hb tetramer ratio. Secondly, I have worked with (in a cardiovascular perspective) fine...

  17. Innovative Large Scale Wireless Sensor Network Architecture Using Satellites and High-Altitude Platforms

    Directory of Open Access Journals (Sweden)

    Yasser Albagory

    2014-03-01

    Full Text Available Wireless sensor network has many applications and very active research area. The coverage span of this network is very important parameter where wide coverage area is a challenge. This paper proposes an architecture for large-scale wireless sensor network (LSWSN based on satellites and the High-Altitude Platforms (HAP where the sensor nodes are located on the ground and a wide coverage sink station may be in the form of a satellite or a network of HAPs. A scenario is described for multilayer LSWSN and a study for the system requirements has been established showing the number of Satellites, HAPs and coverage per each sink according to the elevation angle requirements. The Satellite-HAP-Sensor multilayer LSWSN architecture has the feasibility for effective energy and earth coverage and is optimum for covering largely sparse regions.

  18. Meteorological Support of the Helios World Record High Altitude Flight to 96,863 Feet

    Science.gov (United States)

    Teets, Edward H., Jr.; Donohue, Casey J.; Wright, Patrick T.; DelFrate, John (Technical Monitor)

    2002-01-01

    In characterizing and understanding atmospheric behavior when conducting high altitude solar powered flight research flight planning engineers and meteorologists are able to maximize the use of available airspace and coordinate aircraft maneuvers with pilots to make the best use of changing sun elevation angles. The result of this cooperative research produced a new world record for absolute altitude of a non-rocket powered aircraft of 96,863 ft (29,531.4 m). The Helios prototype solar powered aircraft, with a wingspan of 247 ft (75.0m), reached this altitude on August 13, 2001, off the coast of Kauai, Hawaii. The analyses of the weather characterization, the planning efforts, and the weather-of-the-day summary that led to at record flight are described in this paper.

  19. Implementation of a High-Altitude Balloon Payload to Study Thermospheric Wind Speeds through Redline Airglow Emissions of Atomic Oxygen at 630 nm via a Split-field Etalon Doppler Imager Utilizing a Fabry-Perot Interferometer.

    Science.gov (United States)

    Terry, L. B.; Fullmer, R.; Swenson, C.; Marchant, A.; Hooser, P.; Victors, J.; Muchmore, K.; Yin, L.

    2015-12-01

    Little data exists on the wind velocity characteristics of the upper atmosphere. The Red Line Air Glow Experiment is designed to measure the relative density and velocity of the thermosphere at altitudes approximately ranging between 250 and 350 km. To accomplish this, a Split-Field Etalon Imager will make doppler shift interferometry measurements of the oxygen redline at 630 nm wavelength airglow a using a high altitude balloon platform floating at 36 km. The imager collects up to 10 images per hour. Velocity resolution is within a 5 m/s. The Etalon is thermally controlled to within 1 deg C to achieve this goal. The pointing direction of the sensor is determined post-filght using GPS, IMU and three sun imaging sensors. An experimental star camera is included with a potential pointing accuracy of under 5 arc-min. The instrument first flew from Fort Sumner N,M., on August 26, 2014. Due to the short duration (3.5 hours) of the data collection period on this flight, a second flight was requested and awarded, to take place around September 10, 2015. This flight will allow for data collection over a 24 hour period. Both flight results will be included in the final presentation. This project was designed and built by an undergraduate team including students from physics, aerospace, electrical and mechanical engineering and management at both Utah State University and the University of Maryland Eastern Shores as a NASA's Undergraduate Student Instrument Project (USIP).

  20. Hypoxia: adapting to high altitude by mutating EPAS-1, the gene encoding HIF-2α.

    Science.gov (United States)

    van Patot, Martha C Tissot; Gassmann, Max

    2011-01-01

    Living at high altitude is demanding and thus drives adaptational mechanisms. The Tibetan population has had a longer evolutionary period to adapt to high altitude than other mountain populations such as Andeans. As a result, some Tibetans living at high altitudes do not show markedly elevated red blood cell production as compared to South American high altitude natives such as Quechuas or Aymaras, thereby avoiding high blood viscosity creating cardiovascular risk. Unexpectedly, the responsible mutation(s) reducing red blood cell production do not involve either the gene encoding the blood hormone erythropoietin (Epo), or the corresponding regulatory sequences flanking the Epo gene. Similarly, functional mutations in the hypoxia-inducible transcription factor 1α (HIF-1α) gene that represents the oxygen-dependent subunit of the HIF-1 heterodimer, the latter being the main regulator of over 100 hypoxia-inducible genes, have not been described so far. It was not until very recently that three independent groups showed that the gene encoding HIF-2α, EPAS-1 (Wenger et al. 1997), represents a key gene mutated in Tibetan populations adapted to living at high altitudes (Beall et al. 2010 , Yi et al. 2010 , Simonson et al. 2010). Hypoxia-inducible transcription factors were first identified by the description of HIF-1 (Semenza et al. 1991 , 1992), which was subsequently found to enhance transcription of multiple genes that encode proteins necessary for rescuing from hypoxic exposure, including erythropoietic, angiogenic and glycolytic proteins. Then HIF-2 was identified (Ema et al. 1997 ; Flamme et al. 1997 ; Hogenesch et al. 1997 ; and Tian et al. 1997) and although it is highly similar to HIF-1 and has the potential to bind (Camenisch et al. 2001) and mediate (Mole et al. 2009) many of the same genes as HIF-1, its biological actions in response to hypoxia are distinct from those of HIF-1 (reviewed by Loboda et al. 2010). By now, several of these HIF-2 mediated

  1. Antioxidant and oxidative stress responses of sojourners at high altitude in different climatic temperatures

    Science.gov (United States)

    Sinha, Sanchari; Singh, Som Nath; Saha, Mantu; Kain, T. C.; Tyagi, A. K.; Ray, Uday Sankar

    2010-01-01

    High altitude (HA) is a multi-stressor environment comprising hypobaric hypoxia and cold. Climatic temperature varies with seasonal variation at HA. The present study was undertaken to investigate the effect of ambient temperature on antioxidant profile among sojourners at HA. The study was conducted on sojourners exposed to an altitude of 4,560 m in two different seasons and categorized into two groups (SOJ 1, n = 63, ambient temp. at HA: -6º to +10ºC; SOJ 2, n = 81, ambient temp. at HA: 3º-22ºC). Blood was collected at sea level (SL) and after 4 weeks of HA exposure. Antioxidant enzymes showed significant upregulation in SOJ 2 at HA. In SOJ 1, superoxide dismutase and glutathione peroxidase showed significant upregulation but catalase and glutathione reductase showed significant decrease at HA. Non-enzymatic antioxidants showed significant reduction in SOJ 1 whereas a sustained antioxidant profile was observed in SOJ 2 at HA. Oxidative stress markers showed higher levels in SOJ 1 than SOJ 2 at HA. Differences observed between SOJ 1 and SOJ 2 at HA may be the consequence of different environmental temperatures. Cold stress was higher in SOJ 1 as evidenced from the significantly lower oral temperature in SOJ 1 as compared to SOJ 2. Cold- and hypoxia-induced increase in energy expenditure was significantly high in SOJ 1 than SOJ 2. To conclude, chronic exposure to hypoxia in moderate climatic temperature has a potential preconditioning effect on antioxidant system, but exposure to both cold and hypoxia causes greater oxidative stress due to altered metabolic rate.

  2. Antioxidant and oxidative stress responses of sojourners at high altitude in different climatic temperatures.

    Science.gov (United States)

    Sinha, Sanchari; Singh, Som Nath; Saha, Mantu; Kain, T C; Tyagi, A K

    2010-01-01

    High altitude (HA) is a multi-stressor environment comprising hypobaric hypoxia and cold. Climatic temperature varies with seasonal variation at HA. The present study was undertaken to investigate the effect of ambient temperature on antioxidant profile among sojourners at HA. The study was conducted on sojourners exposed to an altitude of 4,560 m in two different seasons and categorized into two groups (SOJ 1, n=63, ambient temp. at HA: -6 degree to +10degreeC; SOJ 2, n=81, ambient temp. at HA: 3degree-22degreeC). Blood was collected at sea level (SL) and after 4 weeks of HA exposure. Antioxidant enzymes showed significant upregulation in SOJ 2 at HA. In SOJ 1, superoxide dismutase and glutathione peroxidase showed significant upregulation but catalase and glutathione reductase showed significant decrease at HA. Non-enzymatic antioxidants showed significant reduction in SOJ 1 whereas a sustained antioxidant profile was observed in SOJ 2 at HA. Oxidative stress markers showed higher levels in SOJ 1 than SOJ 2 at HA. Differences observed between SOJ 1 and SOJ 2 at HA may be the consequence of different environmental temperatures. Cold stress was higher in SOJ 1 as evidenced from the significantly lower oral temperature in SOJ 1 as compared to SOJ 2. Cold- and hypoxia-induced increase in energy expenditure was significantly high in SOJ 1 than SOJ 2. To conclude, chronic exposure to hypoxia in moderate climatic temperature has a potential preconditioning effect on antioxidant system, but exposure to both cold and hypoxia causes greater oxidative stress due to altered metabolic rate.

  3. Update on high altitude cerebral edema including recent work on the eye.

    Science.gov (United States)

    Willmann, Gabriel; Gekeler, Florian; Schommer, Kai; Bärtsch, Peter

    2014-06-01

    This review summarizes recent research on high altitude cerebral edema (HACE) and on the eye with focus on the retina and optic nerve as visible brain tissue at high altitude. Hemosiderin deposits in the corpus callosum have been characterized as rather specific long-lasting footprints of HACE, indicating a leak of the blood-brain barrier (BBB) and resulting in microhemorrhages. These are compatible with the concept of increased capillary pressure due to venous outflow limitation as suggested by Wilson et al. There are no human data on the role of vascular permeability in HACE, while animal models of uncertain relevance for human HACE suggest that an impaired integrity of the BBB through VEGF and ROS is more important than hemodynamic changes. Examinations by ultrasound show an inconsistent increase of the optic nerve sheath diameter, whereas unequivocal optic disc swelling (ODS), increased retinal vessel diameter, as well as retinal vessel leakage occur at high altitude. However, whether these morphological changes correlate with symptoms of AMS as a possible precursor of HACE or high altitude headache supporting the concept of venous outflow limitation remains questionable and is discussed in detail in this article.

  4. Genomic analysis of natural selection and phenotypic variation in high-altitude mongolians.

    Directory of Open Access Journals (Sweden)

    Jinchuan Xing

    Full Text Available Deedu (DU Mongolians, who migrated from the Mongolian steppes to the Qinghai-Tibetan Plateau approximately 500 years ago, are challenged by environmental conditions similar to native Tibetan highlanders. Identification of adaptive genetic factors in this population could provide insight into coordinated physiological responses to this environment. Here we examine genomic and phenotypic variation in this unique population and present the first complete analysis of a Mongolian whole-genome sequence. High-density SNP array data demonstrate that DU Mongolians share genetic ancestry with other Mongolian as well as Tibetan populations, specifically in genomic regions related with adaptation to high altitude. Several selection candidate genes identified in DU Mongolians are shared with other Asian groups (e.g., EDAR, neighboring Tibetan populations (including high-altitude candidates EPAS1, PKLR, and CYP2E1, as well as genes previously hypothesized to be associated with metabolic adaptation (e.g., PPARG. Hemoglobin concentration, a trait associated with high-altitude adaptation in Tibetans, is at an intermediate level in DU Mongolians compared to Tibetans and Han Chinese at comparable altitude. Whole-genome sequence from a DU Mongolian (Tianjiao1 shows that about 2% of the genomic variants, including more than 300 protein-coding changes, are specific to this individual. Our analyses of DU Mongolians and the first Mongolian genome provide valuable insight into genetic adaptation to extreme environments.

  5. Pregnancy at high altitude in the Andes leads to increased total vessel density in healthy newborns

    NARCIS (Netherlands)

    Gassmann, N.N. (Norina N.); H.A. van Elteren (Hugo); T.G. Goos (Tom); Morales, C.R. (Claudia R.); Rivera-Ch, M. (Maria); D.S. Martin; Peralta, P.C. (Patricia Cabala); Del Carpio, A.P. (Agustin Passano); MacHaca, S.A. (Saul Aranibar); Huicho, L. (Luis); I.K.M. Reiss (Irwin); Gassmann, M. (Max); R.C.J. de Jonge (Rogier)

    2016-01-01

    markdownabstractThe developing human fetus is able to cope with the physiological reduction in oxygen supply occurring in utero. However, it is not known if microvascularization of the fetus is augmented when pregnancy occurs at high altitude. Fifty-three healthy term newborns in Puno, Peru (3,840

  6. On the High Altitude Platform (HAP W-CDMA System Capacity

    Directory of Open Access Journals (Sweden)

    L. de Haro-Ariet

    2004-06-01

    Full Text Available The performance of a downlink power control model, based on a n-thpower distance law, is evaluated for high altitude platform station(HAPS W-CDMA systems. The downlink capacity using this model iscompared with the uplink capacity. It is shown that the uplink capacityis higher than the downlink capacity.

  7. Unchanged cerebral blood flow and oxidative metabolism after acclimatization to high altitude

    DEFF Research Database (Denmark)

    Møller, Kirsten; Paulson, Olaf B; Hornbein, Thomas F.

    2002-01-01

    . At high altitude at rest, arterial carbon dioxide tension, oxygen saturation, and oxygen tension were significantly reduced, and arterial oxygen content was increased because of an increase in hemoglobin concentration. Global cerebral blood flow was similar in the four conditions. Cerebral oxygen delivery...

  8. High altitude wind resource in the Middle East

    Science.gov (United States)

    Yip, Chak Man Andrew; Gunturu, Udaya B.; Stenchikov, Georgiy L.

    2016-04-01

    This study presents a first identification of areas favorable to Airborne Wind Energy (AWE) Systems deployment in the Middle East and illustrates their diurnal and seasonal characteristics. Optimal heights of AWE system deployment are computed. The AWE literature has conventionally used a top-down approach where AWE potentials are estimated as a fraction of wind power density. This study takes the bottom-up approach where the regional AWE potentials are estimated using realistic machine specification with assumptions upon deployment conditions. The annual energy production per capita illustrates the potential of AWE systems in fulfilling electricity needs at the current level for several countries in the region. Our estimate also compares favorably to the near-surface wind power potential using identical data source from a previous study. In addition, the non-monotonicity in the vertical profile is examined for areas with potential LLJ influences, where behaviors in wind speed and direction similar to that of inertial oscillations are identified.

  9. Tropical deep convective life cycle: Cb-anvil cloud microphysics from high altitude aircraft observations

    Directory of Open Access Journals (Sweden)

    W. Frey

    2014-05-01

    Full Text Available The case study presented here focusses on the life cycle of clouds in a tropical deep convective system. During the SCOUT-O3 campaign from Darwin, Northern Australia, the Hector storm system has been probed by the Geophysica high altitude aircraft. Clouds were observed by in situ particle probes, a backscatter sonde, and a miniature lidar. Additionally, aerosol number concentrations have been measured. On 30 November 2005 a double flight took place and Hector was probed throughout its life cycle in its developing, mature, and dissipating stage. The two flights were four hours apart and focussed on the anvil region of Hector in altitudes between 10.5 km and 18.8 km (i.e. above 350 K potential temperature. Trajectory calculations and ozone measurements have been used to identify that the same cloud air masses have been probed in both flights. The size distributions derived from the measurements not only show a change with increasing altitude but also with the evolution of Hector. Clearly different aerosol to cloud particle ratios as well as varying ice crystal morphology have been found for the different development stages of Hector, indicating a change in freezing mechanisms. The development phase exhibits the smallest ice particles (up to 300 μm with a rather uniform morphology. This is indicative for rapid glaciation during Hector's development. Sizes of ice crystals are largest in the mature stage (larger 1.6 mm and even exceed those of some continental tropical deep convective clouds, also in their number concentrations. The backscatter properties and particle images show a change from frozen droplets in the developing phase to rimed and aggregated particles. The clouds in the dissipating stage have a large vertical extend (roughly 6 km though optically thin and persist for at least 6 h. This poses a high potential for affecting the tropical tropopause layer background conditions regarding humidity, e.g. through facilitating subvisible

  10. Tropical deep convective life cycle: Cb-anvil cloud microphysics from high altitude aircraft observations

    Science.gov (United States)

    Frey, W.; Borrmann, S.; Fierli, F.; Weigel, R.; Mitev, V.; Matthey, R.; Ravegnani, F.; Sitnikov, N. M.; Ulanovsky, A.; Cairo, F.

    2014-05-01

    The case study presented here focusses on the life cycle of clouds in a tropical deep convective system. During the SCOUT-O3 campaign from Darwin, Northern Australia, the Hector storm system has been probed by the Geophysica high altitude aircraft. Clouds were observed by in situ particle probes, a backscatter sonde, and a miniature lidar. Additionally, aerosol number concentrations have been measured. On 30 November 2005 a double flight took place and Hector was probed throughout its life cycle in its developing, mature, and dissipating stage. The two flights were four hours apart and focussed on the anvil region of Hector in altitudes between 10.5 km and 18.8 km (i.e. above 350 K potential temperature). Trajectory calculations and ozone measurements have been used to identify that the same cloud air masses have been probed in both flights. The size distributions derived from the measurements not only show a change with increasing altitude but also with the evolution of Hector. Clearly different aerosol to cloud particle ratios as well as varying ice crystal morphology have been found for the different development stages of Hector, indicating a change in freezing mechanisms. The development phase exhibits the smallest ice particles (up to 300 μm) with a rather uniform morphology. This is indicative for rapid glaciation during Hector's development. Sizes of ice crystals are largest in the mature stage (larger 1.6 mm) and even exceed those of some continental tropical deep convective clouds, also in their number concentrations. The backscatter properties and particle images show a change from frozen droplets in the developing phase to rimed and aggregated particles. The clouds in the dissipating stage have a large vertical extend (roughly 6 km) though optically thin and persist for at least 6 h. This poses a high potential for affecting the tropical tropopause layer background conditions regarding humidity, e.g. through facilitating subvisible cirrus formation, and

  11. Impact of high altitude on the hepatic fatty acid oxidation and synthesis in rats

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Qian [Department of General Surgery, Hepatic-biliary-pancreatic Institute, Lanzhou University Second Hospital, Lanzhou (China); Department of Pediatrics, Lanzhou University Second Hospital, Lanzhou (China); Shao, Yuan; Wang, Ying Zhen [Department of General Surgery, Hepatic-biliary-pancreatic Institute, Lanzhou University Second Hospital, Lanzhou (China); Jing, Yu Hong [Institute of Anatomy, School of Basic Medicine, Lanzhou University, Lanzhou (China); Zhang, You Cheng, E-mail: zhangychmd@126.com [Department of General Surgery, Hepatic-biliary-pancreatic Institute, Lanzhou University Second Hospital, Lanzhou (China)

    2014-04-04

    Highlights: • Acute exposure to high altitude (HA) increased hepatic fatty acid (FA) β-oxidation. • Acute exposure of rats to HA increased hepatic FA synthesis. • PPARα and AMPK can regulate the FA metabolism. • FA may be a key energy fuel and a compensation for CHO during acute exposure to HA. • The acute changes of FA metabolism may be a mechanism of acclimatization. - Abstract: High altitude (HA) affects energy metabolism. The impact of acute and chronic HA acclimatization on the major metabolic pathways is still controversial. In this study, we aimed to unveil the impact of HA on the key enzymes involved in the fatty acid (FA) metabolism in liver. Rats were exposed to an altitude of 4300 m for 30 days and the expressions of two key proteins involved in FA β-oxidation (carnitine palmitoyl transferase I, CPT-I; and peroxisome proliferator-activated receptor alpha, PPARα), two proteins involved in FA synthesis (acetyl CoA carboxylase-1, ACC-1; and AMP-activated protein kinase, AMPK), as well as the total ketone body in the liver and the plasma FFAs were examined. Rats without HA exposure were used as controls. We observed that the acute exposure of rats to HA (3 days) led to a significant increase in the expressions of CPT-I and PPARα and in the total hepatic ketone body. Longer exposure (15 days) caused a marked decrease in the expression of CPT-I and PPARα. By 30 days after HA exposure, the expression levels of CPT-I and PPARα returned to the control level. The hepatic ACC-1 level showed a significant increase in rats exposed to HA for 1 and 3 days. In contrast, the hepatic level of AMPK showed a significant reduction throughout the experimental period. Plasma FFA concentrations did not show any significant changes following HA exposure. Thus, increased hepatic FA oxidation and synthesis in the early phase of HA exposure may be among the important mechanisms for the rats to respond to the hypoxic stress in order to acclimatize themselves to the

  12. High energy nucleonic component of cosmic rays at mountain altitudes

    CERN Document Server

    Stora, Raymond Félix

    The diffusion equations describing the unidimensional propagation of .the high energy nucleonic component of cosmic rays throughout the atmosphere are sol"V'ed under two assumptions: (l) The nucleon-nucleon collisions are described according to Fermi's therlnOdynamical model involving completely inelastic pion and.nucleon-antinucleon pair production. (2) A somewhat opposite assumption is made assuming partially elastic collisions without nucleon-anti.nucleon pair production. Due to the present inaccuracy of experiments, we are able to derive only tentati v.e conclusions. The values computed under both hypotheses for the absorption mean free path and the charged to neutral particles ratio are found in acceptable ranges when compared to experimental data. The diffeential energy spectrum at a given depth is always found steeper than the primary, and steeper than indicated by experimental values if the primary is taken proportional to the 2.5 inverse power of energy.

  13. A preliminary design and analysis of an advanced heat-rejection system for an extreme altitude advanced variable cycle diesel engine installed in a high-altitude advanced research platform

    Science.gov (United States)

    Johnston, Richard P.

    1992-01-01

    Satellite surveillance in such areas as the Antarctic indicates that from time to time concentration of ozone grows and shrinks. An effort to obtain useful atmospheric data for determining the causes of ozone depletion would require a flight capable of reaching altitudes of at least 100,000 ft and flying subsonically during the sampling portion of the mission. A study of a heat rejection system for an advanced variable cycle diesel (AVCD) engine was conducted. The engine was installed in an extreme altitude, high altitude advanced research platform. Results indicate that the waste heat from an AVCD engine propulsion system can be rejected at the maximum cruise altitude of 120,000 ft. Fifteen performance points, reflecting the behavior of the engine as the vehicle proceeded through the mission, were used to characterize the heat exchanger operation. That portion of the study is described in a appendix titled, 'A Detailed Study of the Heat Rejection System for an Extreme Altitude Atmospheric Sampling Aircraft,' by a consultant, Mr. James Bourne, Lytron, Incorporated.

  14. Experimental Study on Combustion Characteristics of Fire in High-altitude Railway Tunnels%高海拔铁路隧道火灾燃烧特性试验研究

    Institute of Scientific and Technical Information of China (English)

    张念; 谭忠盛; 毛军; 万飞; 郭峰

    2011-01-01

    Full-scale model tests were conducted in the slope of Guanjiao Tunnel (32.645 km) , which is a high-altitude super-long railway tunnel, to research the burning characteristics of high-altitude tunnel fire. The distribution of the temperature and smoke under different fire-scale conditions inside the tunnel was measured. Analysis on the experimental results showed that temperature at the tunnel vault was higher than temperature near the tunnel centerline; temperature near the fire was highest; with the distance to the fire increasing, temperature decreased; longitudinal wind had an important influence on smoke distribution, temperature at downstream was higher than that at upstream. Finally, some recommendations to the fire disaster-relief design of the high-altitude tunnel were put forward according to the analysis of test results.%采用火灾模型试验的研究方式,在高海拔特长铁路隧道——关角隧道( 32.645 km)的斜井内进行火灾燃烧的全尺寸模型试验,测得不同火灾规模条件下隧道内温度和烟气分布,通过分析试验结果,得到高海拔隧道火灾的燃烧特性.研究结果表明:隧道拱顶处温度高于隧道中心线附近温度;火源附近温度最高,隧道内各位置温度随着距火源点距离增加而降低;纵向风速对隧道内烟气分布有重要影响,火源下游温度高于上游温度.结合试验的分析结果,就高海拔隧道火灾防灾救援设计提出建议.

  15. Preliminary Study on the Standards of Operation Ventilation of Diesel Traction in High- altitude Tunnel%高海拔隧道内燃牵引运营通风标准研究

    Institute of Scientific and Technical Information of China (English)

    孙三祥; 张云霞; 李国良; 杨国柱; 谢君泰

    2011-01-01

    Research purposes: In order to solve the problem of standards about allowable concentration of harmful emission gases to operation ventilation of diesel traction in high - altitude ( >3 000 m) tunnel. Based on the comparison results of operation ventilation standards and allowable concentrations of harmful emission gases, CO, NO2 control of the maximum allowable concentration, the suggestion standards of operation ventilation control of diesel traction in high altitude tunnel is presented.Research conclusions: The national standards is more stringent than the developed countrie' s. The suggestion standards of operation ventilation control of diesel traction in high altitude tunnel are that time weightd average ( TWA) of Noχ (nitragen dioxide level) is 10 mg/m3 in workday, short term(30 min)exposure limit of Noχ≤30 mg/m3. TWA of CO is 30 mg/m3 in workday, short term(30 min)exposure limit of CO≤90 mg/m3.%目前国内高海拔地区(海拔>3 000 m)隧道内燃牵引运营通风设计中,有害气体容许浓度没有相应的规范可参照.通过国内外高、低海拔地区CO、NO2最高容许浓度的比较,国内外隧道运营通风与环境控制标准检索、分析,提出高海拔隧道内燃牵引运营通风控制标准建议值.研究结论:国内相关规范(标准)规定的有害气体最高容许浓度比国外发达国家的标准要求高.初步建议高海拔运营隧道内空气中内燃机车废气的容许浓度:NOx(以NO2计):工作日内平均容许浓度为10 mg/m3,工作日内任何一次30 min内接触废气的平均浓度不超过30 mg/m3.CO:工作日内平均容许浓度为30 mg/m3,工作日内任何一次30 min内接触废气的平均浓度不超过90 mg/m3.

  16. Texture classification of vegetation cover in high altitude wetlands zone

    Science.gov (United States)

    Wentao, Zou; Bingfang, Wu; Hongbo, Ju; Hua, Liu

    2014-03-01

    The aim of this study was to investigate the utility of datasets composed of texture measures and other features for the classification of vegetation cover, specifically wetlands. QUEST decision tree classifier was applied to a SPOT-5 image sub-scene covering the typical wetlands area in Three River Sources region in Qinghai province, China. The dataset used for the classification comprised of: (1) spectral data and the components of principal component analysis; (2) texture measures derived from pixel basis; (3) DEM and other ancillary data covering the research area. Image textures is an important characteristic of remote sensing images; it can represent spatial variations with spectral brightness in digital numbers. When the spectral information is not enough to separate the different land covers, the texture information can be used to increase the classification accuracy. The texture measures used in this study were calculated from GLCM (Gray level Co-occurrence Matrix); eight frequently used measures were chosen to conduct the classification procedure. The results showed that variance, mean and entropy calculated by GLCM with a 9*9 size window were effective in distinguishing different vegetation types in wetlands zone. The overall accuracy of this method was 84.19% and the Kappa coefficient was 0.8261. The result indicated that the introduction of texture measures can improve the overall accuracy by 12.05% and the overall kappa coefficient by 0.1407 compared with the result using spectral and ancillary data.

  17. The paradox of extreme high-altitude migration in bar-headed geese Anser indicus

    Science.gov (United States)

    Hawkes, L.A.; Balachandran, S.; Batbayar, N.; Butler, P.J.; Chua, B.; Douglas, D.C.; Frappell, P.B.; Hou, Y.; Milsom, W.K.; Newman, S.H.; Prosser, D.J.; Sathiyaselvam, P.; Scott, G.R.; Takekawa, John Y.; Natsagdorj, T.; Wikelski, M.; Witt, M.J.; Yan, B.; Bishop, C.M.

    2012-01-01

    Bar-headed geese are renowned for migratory flights at extremely high altitudes over the world's tallest mountains, the Himalayas, where partial pressure of oxygen is dramatically reduced while flight costs, in terms of rate of oxygen consumption, are greatly increased. Such a mismatch is paradoxical, and it is not clear why geese might fly higher than is absolutely necessary. In addition, direct empirical measurements of high-altitude flight are lacking. We test whether migrating bar-headed geese actually minimize flight altitude and make use of favourable winds to reduce flight costs. By tracking 91 geese, we show that these birds typically travel through the valleys of the Himalayas and not over the summits. We report maximum flight altitudes of 7290 m and 6540 m for southbound and northbound geese, respectively, but with 95 per cent of locations received from less than 5489 m. Geese travelled along a route that was 112 km longer than the great circle (shortest distance) route, with transit ground speeds suggesting that they rarely profited from tailwinds. Bar-headed geese from these eastern populations generally travel only as high as the terrain beneath them dictates and rarely in profitable winds. Nevertheless, their migration represents an enormous challenge in conditions where humans and other mammals are only able to operate at levels well below their sea-level maxima.

  18. Ground-high altitude joint detection of ozone and nitrogen oxides in urban areas of Beijing

    Institute of Scientific and Technical Information of China (English)

    Pengfei Chen; Qiang Zhang; Jiannong Quan; Yang Gao; Delong Zhao; Junwang Meng

    2013-01-01

    Based on observational data of ozone (O3) and nitrogen oxide (NOx) mixing ratios on the ground and at high altitude in urban areas of Beijing during a period of six days in November 2011,the temporal and spatial characteristics of mixing ratios were analyzed.The major findings include:urban O3 mixing ratios are low and NOx mixing ratios are always high near the road in November.Vertical variations of the gases are significantly different in and above the planetary boundary layer.The mixing ratio of O3 is negatively correlated with that of NOx and they are positively correlated with air temperature,which is the main factor directly causing vertical variation of O3 and NOx mixing ratios at 600-2100 m altitude.The NOx mixing ratios elevated during the heating period,while the O3 mixing ratios decreased:these phenomena are more significant at high altitudes compared to lower altitudes.During November,air masses in the urban areas of Beijing are brought bynorthwesterly winds,which transport O3 and NOx at low mixing ratios.Due to Beijing's natural geographical location,northwest air currents are beneficial to the dilution and dispersion of pollutants,which can result in lower O3 and NOx background values in the Beijing urban area.

  19. Interplanetary dust particles, not wind blown dust, control high altitude ice clouds on Mars

    Science.gov (United States)

    Hartwick, Victoria; Toon, Owen B.

    2016-10-01

    Water ice clouds on Mars are commonly observed at high altitudes. However, current generation Mars three-dimensional general circulation models (GCM) struggle to reproduce clouds above approximately 20-30 km. On Mars, as on Earth, ice cloud formation likely initiates by heterogeneous nucleation, which requires a population of suspended ice nuclei contiguous with supersaturated atmospheric water vapor. Although supersaturation is observed at high altitudes and has been reproduced in models, models predict very few ice nuclei. The small number of ice nuclei in the upper atmosphere is due to the assumption in Mars GCMs that the only source of ice nuclei is dust from the Martian surface. However, terrestrial mesospheric noctilucent clouds have been shown to form by ice nucleation on particles originating from ablated micrometeroids. Therefore, it is reasonable to assume that a population of micrometeoric ablation biproducts on Mars exists and can act as a site for cloud nucleation at high altitudes. We present simulations using the Community Atmosphere Model for Mars (MarsCAM) based on the National Center for Atmospheric Research (NCAR) Community Atmosphere Model for Earth,coupled with a physically based, state-of-the-art cloud and dust physics model, the Community Aerosol and Radiation Model for Atmospheres (CARMA) to show that ablating micrometeoroids can yield abundant ice nuclei throughout the upper atmosphere of Mars. We find that simulations including a constant annual micrometeoroid flux allows us to reproduce the observed properties of high altitude water ice clouds including vertical distribution and particle size. In general, effective radius decreases with increasing altitude. We have additionally explored the impact of variable ablation rates. Preliminary results suggest that relatively high ablation rates, near or greater than 50%, are required to reproduce observed cloud features.

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

    Directory of Open Access Journals (Sweden)

    Caroline Buss

    2006-02-01

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

  1. Changing Hydrology in Glacier-fed High Altitude Andean Peatbogs

    Science.gov (United States)

    Slayback, D. A.; Yager, K.; Baraer, M.; Mohr, K. I.; Argollo, J.; Wigmore, O.; Meneses, R. I.; Mark, B. G.

    2012-12-01

    Montane peatbogs in the glacierized Andean highlands of Peru and Bolivia provide critical forage for camelids (llama and alpaca) in regionally extensive pastoral agriculture systems. During the long dry season, these wetlands often provide the only available green forage. A key question for the future of these peatbog systems, and the livelihoods they support, is the impact of climate change and glacier recession on their hydrology, and thus forage production. We have already documented substantial regional glacier recession, of, on average, approximately 30% of surface area over the past two decades. As glaciers begin to retreat under climate change, there is initially a period of increased meltwater outflow, culminating in a period of "peak water", and followed by a continual decline in outflows. Based on previous work, we know that some glaciers in the region have already passed peak water conditions, and are now declining. To better understand the impacts of these processes on peatbog hydrology and productivity, we have begun collecting a variety of surface data at several study sites in both Bolivia and Peru. These include precipitation, stream flow, water levels, water chemistry and isotope analyses, and peatbog biodiversity and biomass. These measurements will be used in conjunction with a regional model driven by satellite data to predict likely future impacts. We will present the results from these initial surface measurements, and an overview of satellite datasets to be used in the regional model.

  2. Chemical Analysis of Pottery Demonstrates Prehistoric Origin for High-Altitude Alpine Dairying.

    Science.gov (United States)

    Carrer, Francesco; Colonese, André Carlo; Lucquin, Alexandre; Petersen Guedes, Eduardo; Thompson, Anu; Walsh, Kevin; Reitmaier, Thomas; Craig, Oliver E

    2016-01-01

    The European high Alps are internationally renowned for their dairy produce, which are of huge cultural and economic significance to the region. Although the recent history of alpine dairying has been well studied, virtually nothing is known regarding the origins of this practice. This is due to poor preservation of high altitude archaeological sites and the ephemeral nature of transhumance economic practices. Archaeologists have suggested that stone structures that appear around 3,000 years ago are associated with more intense seasonal occupation of the high Alps and perhaps the establishment of new economic strategies. Here, we report on organic residue analysis of small fragments of pottery sherds that are occasionally preserved both at these sites and earlier prehistoric rock-shelters. Based mainly on isotopic criteria, dairy lipids could only be identified on ceramics from the stone structures, which date to the Iron Age (ca. 3,000-2,500 BP), providing the earliest evidence of this practice in the high Alps. Dairy production in such a marginal environment implies a high degree of risk even by today's standards. We postulate that this practice was driven by population increase and climate deterioration that put pressure on lowland agropastoral systems and the establishment of more extensive trade networks, leading to greater demand for highly nutritious and transportable dairy products.

  3. Lower obesity rate during residence at high altitude among a military population with frequent migration: a quasi experimental model for investigating spatial causation.

    Directory of Open Access Journals (Sweden)

    Jameson D Voss

    Full Text Available We sought to evaluate whether residence at high altitude is associated with the development of obesity among those at increased risk of becoming obese. Obesity, a leading global health priority, is often refractory to care. A potentially novel intervention is hypoxia, which has demonstrated positive long-term metabolic effects in rats. Whether or not high altitude residence confers benefit in humans, however, remains unknown. Using a quasi-experimental, retrospective study design, we observed all outpatient medical encounters for overweight active component enlisted service members in the U.S. Army or Air Force from January 2006 to December 2012 who were stationed in the United States. We compared high altitude (>1.96 kilometers above sea level duty assignment with low altitude (<0.98 kilometers. The outcome of interest was obesity related ICD-9 codes (278.00-01, V85.3x-V85.54 by Cox regression. We found service members had a lower hazard ratio (HR of incident obesity diagnosis if stationed at high altitude as compared to low altitude (HR 0.59, 95% confidence interval [CI] 0.54-0.65; p<0.001. Using geographic distribution of obesity prevalence among civilians throughout the U.S. as a covariate (as measured by the Centers for Disease Control and Prevention and the REGARDS study also predicted obesity onset among service members. In conclusion, high altitude residence predicts lower rates of new obesity diagnoses among overweight service members in the U.S. Army and Air Force. Future studies should assign exposure using randomization, clarify the mechanism(s of this relationship, and assess the net balance of harms and benefits of high altitude on obesity prevention.

  4. Decreased plasma soluble erythropoietin receptor in high-altitude excessive erythrocytosis and Chronic Mountain Sickness.

    Science.gov (United States)

    Villafuerte, Francisco C; Macarlupú, José Luis; Anza-Ramírez, Cecilia; Corrales-Melgar, Daniela; Vizcardo-Galindo, Gustavo; Corante, Noemí; León-Velarde, Fabiola

    2014-12-01

    Excessive erythrocytosis (EE) is the hallmark of chronic mountain sickness (CMS), a prevalent syndrome in high-altitude Andean populations. Although hypoxemia represents its underlying stimulus, why some individuals develop EE despite having altitude-normal blood erythropoietin (Epo) concentration is still unclear. A soluble form of the Epo receptor (sEpoR) has been identified in human blood and competes directly for Epo with its membrane counterpart (mEpoR). Thus, reduced levels of circulating sEpoR could lead to higher Epo availability and ultimately to EE. We characterized the relationship between Epo and sEpoR, with hematocrit and hemoglobin concentration in healthy highlanders and CMS patients at 4,340 m in Cerro de Pasco, Peru. Our results show that EE patients show decreased plasma sEpoR levels and can be subdivided into two subgroups of normal and high plasma Epo concentration for the altitude of residence, with hemoglobin concentration rising exponentially with an increasing Epo-to-sEpoR ratio (Epo/sEpoR). Also, we showed that the latter varies as an inverse exponential function of arterial pulse O2 saturation. Our findings suggests that EE is strongly associated with higher Epo/sEpoR values, leading to elevated plasma Epo availability to bind mEpoR, and thereby a stronger stimulus for augmented erythropoiesis. Differences in the altitude normal and high Epo CMS patients with a progressively higher Epo/sEpoR supports the hypothesis of the existence of two genetically different subgroups suffering from EE and possibly different degrees of adaptation to chronic high-altitude hypoxia.

  5. Placental villus morphology in relation to maternal hypoxia at high altitude.

    Science.gov (United States)

    Espinoza, J; Sebire, N J; McAuliffe, F; Krampl, E; Nicolaides, K H

    2001-07-01

    Pregnancy at high altitude is associated with maternal hypoxaemic hypoxia with resultant intervillus blood hypoxia. Maternal haemoglobin concentration and blood gases were measured in pregnant women in two cities in Peru; Lima at sea level (n=18) and Cerro de Pasco at 4300 metres above sea level (n=12). Following delivery, placental sections from both groups were examined histomorphometrically using an image analysis system. Villus diameter, villus cross-sectional area, capillary diameter, capillary cross-sectional area and the percentage of villus cross-sectional area occupied by villus capillaries were calculated and parameters were compared between the two altitude groups. Maternal haemoglobin concentration and maternal blood pH were significantly higher, and maternal pO(2), pCO(2)and O(2)saturation were significantly lower in the high altitude group compared to those at sea level. The villus vessel area as a percentage of villus cross-sectional area and capillary diameter were significantly greater in the cases from the high altitude group and villus vessel area as a percentage of the villus cross-sectional area was significantly related to maternal pO(2)(r=-0.7, P=0.01), and maternal pCO(2)(r=0.7, P=0.02), but multiple regression analysis demonstrated that only pO(2)remained significantly independently associated with these villus histological findings (P=0.03). Placental terminal villi from term pregnancies at high altitude show different morphological features from pregnancies at sea level, and these changes are primarily related to maternal pO(2). The predominant morphological alteration is an increase in villus capillary diameter and therefore of the proportion of villus cross-sectional area occupied by capillary lumens.

  6. The role of oxygen-increased respirator in humans ascending to high altitude

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    Shen Guanghao

    2012-08-01

    Full Text Available Abstract Background Acute mountain sickness (AMS is common for people who live in low altitude areas ascending to the high altitude. Many instruments have been developed to treat mild cases of AMS. However, long-lasting and portable anti-hypoxia equipment for individual is not yet available. Methods Oxygen-increased respirator (OIR has been designed to reduce the risk of acute mountain sickness in acute exposure to low air pressure. It can increase the density of oxygen by increasing total atmospheric pressure in a mask. Male subjects were screened, and eighty-eight were qualified to perform the experiments. The subjects were divided into 5 groups and were involved in some of the tests at 4 different altitudes (Group 1, 2: 3700 m; Group 3,4,5: 4000 m, 4700 m, 5380 m with and without OIR. These tests include heart rate, saturation of peripheral oxygen (SpO2, malondialdehyde (MDA, superoxide dismutase (SOD, blood lactate (BLA and PWC (physical work capacity -170. Results The results showed that higher SpO2, lower heart rate (except during exercise and better recovery of heart rate were observed from all the subjects ’with OIR’ compared with ’without OIR’ (P Conclusions We suggested that OIR may play a useful role in protecting people ascending to high altitude before acclimatization.

  7. Sleep quality alterations in healthy workers at high altitude in Yushu area

    Institute of Scientific and Technical Information of China (English)

    Wu Tianyi; Li Wenxiang; Zhang Jianqing; Qi Shengui; Hao Lijuan; Wen Jialin

    2013-01-01

    During the period of reconstruction after Yushu Earthquake,a large number of sea-level or lowland workers ascended there and worked at altitudes between 3750 m and 4878 m which is a hypoxic environment.To investigate the sleep quality at that altitude,we performed two full polysomnographies (PSGs) in 10 volunteers,who were healthy male workers,aged 31±6.6,born and living at sea level,without experience of pre-altitude exposure.The assessment of subjective sleep quality was performed twice in each volunteer.The first investigations were carried out at sea level in Jinan city (pB=760 torr,1 torr=133.322 4 Pa).The second studies were performed at an altitude of 3750 m (pB=416 tonr) in Yushu Jiegu in the same 10 workers after they lived and worked at that altitude for 5 months.At sea level,workers presented a normal sleep structure and a higher oxygenation during sleep.However,as compared to sea-level sleep,at 3750 m,workers had a shorter total sleep time (TST) (p < 0.001),a longer stage 1 non-rapid eye movement (nREM) sleep (p < 0.05) and a shorter 3+4 nREM and rapid eye movement (REM) sleep (p < 0.05) with a severe sleep hypoxemia (p < 0.01).Our data suggested that sea-level workers revealed a disturbed sleep and a bad sleep quality with a significant sleep hypoxemia at altitude of 3750 m.Strengthening the prevention and treatment are thereby sorely necessary.

  8. Disturbances in Maternal Steroidogenesis and Appearance of Intrauterine Growth Retardation at High-Altitude Environments Are Established from Early Pregnancy. Effects of Treatment with Antioxidant Vitamins.

    Science.gov (United States)

    Parraguez, Victor H; Mamani, Sandra; Cofré, Eileen; Castellaro, Giorgio; Urquieta, Bessie; De Los Reyes, Mónica; Astiz, Susana; Gonzalez-Bulnes, Antonio

    2015-01-01

    Pregnancies at high-altitudes are influenced by hypoxia and oxidative stress and frequently affected by IUGR. However, a common thought is that early pregnant women visiting altitude have no major complications for gestation development, since IUGR is developed during the second half of pregnancy. Thus, using a well-characterized sheep-model, we aimed to determine whether long- and/or short-term exposure to high-altitude may affect maternal steroidogenesis and therefore embryo-fetal growth from conception. The second aim was to differentiate the relative role of hypoxia and oxidative stress by assessing the effects of supplementation with antioxidant agents during this early-pregnancy stage, which were previously found to be useful to prevent IUGR. The results indicate that both long- and short-term exposure to high-altitude causes disturbances in maternal ovarian steroidogenesis and negatively affects embryo-fetal growth already during the very early stages of gestation, with the consequences being even worsened in newcomers to high-altitude. The supply of antioxidant during this period only showed discrete effects for preventing IUGR. In conclusion, the present study gives a warning for clinicians about the risks for early-pregnant women when visiting high-altitude regions and suggests the need for further studies on the effects of the length of exposure and on the interaction of the exposure with the pregnancy stage.

  9. Disturbances in Maternal Steroidogenesis and Appearance of Intrauterine Growth Retardation at High-Altitude Environments Are Established from Early Pregnancy. Effects of Treatment with Antioxidant Vitamins.

    Directory of Open Access Journals (Sweden)

    Victor H Parraguez

    Full Text Available Pregnancies at high-altitudes are influenced by hypoxia and oxidative stress and frequently affected by IUGR. However, a common thought is that early pregnant women visiting altitude have no major complications for gestation development, since IUGR is developed during the second half of pregnancy. Thus, using a well-characterized sheep-model, we aimed to determine whether long- and/or short-term exposure to high-altitude may affect maternal steroidogenesis and therefore embryo-fetal growth from conception. The second aim was to differentiate the relative role of hypoxia and oxidative stress by assessing the effects of supplementation with antioxidant agents during this early-pregnancy stage, which were previously found to be useful to prevent IUGR. The results indicate that both long- and short-term exposure to high-altitude causes disturbances in maternal ovarian steroidogenesis and negatively affects embryo-fetal growth already during the very early stages of gestation, with the consequences being even worsened in newcomers to high-altitude. The supply of antioxidant during this period only showed discrete effects for preventing IUGR. In conclusion, the present study gives a warning for clinicians about the risks for early-pregnant women when visiting high-altitude regions and suggests the need for further studies on the effects of the length of exposure and on the interaction of the exposure with the pregnancy stage.

  10. Experimental characterization of the COndensation PArticle counting System for high altitude aircraft-borne application [Discussion paper

    OpenAIRE

    Weigel, Ralf; Hermann, Markus; Curtius, Joachim; Voigt, Christiane; Walter, Saskia; Böttger, Thomas; Lepukhov, Boris; Belyaev, Gennady; Borrmann, Stephan

    2008-01-01

    his study aims at a detailed characterization of an ultra-fine aerosol particle counting system for operation on board the Russian high altitude research aircraft M-55 "Geophysica" (maximum ceiling of 21 km). The COndensation PArticle counting Systems (COPAS) consists of an aerosol inlet and two dual-channel continuous flow Condensation Particle Counters (CPCs). The aerosol inlet, adapted for COPAS measurements on board the M-55 "Geophysica", is described concerning aspiration, transmissio...

  11. Lung function and breathing pattern in subjects developing high altitude pulmonary edema.

    Directory of Open Access Journals (Sweden)

    Christian F Clarenbach

    Full Text Available INTRODUCTION: The purpose of the study was to comprehensively evaluate physiologic changes associated with development of high altitude pulmonary edema (HAPE. We tested whether changes in pulmonary function and breathing pattern would herald clinically overt HAPE at an early stage. METHODS: In 18 mountaineers, spirometry, diffusing capacity, nitrogen washout, nocturnal ventilation and pulse oximetry were recorded at 490 m and during 3 days after rapid ascent to 4559 m. Findings were compared among subjects developing HAPE and those remaining well (controls. RESULTS: In 8 subjects subsequently developing radiographically documented HAPE at 4559 m, median FVC declined to 82% of low altitude baseline while closing volume increased to 164% of baseline (P<0.05, both instances. In 10 controls, FVC decreased slightly (to 93% baseline, P<0.05 but significantly less than in subjects with HAPE and closing volume remained unchanged. Sniff nasal pressure was reduced in both subjects with and without subsequent HAPE. During nights at 4559 m, mean nocturnal oxygen saturation dropped to lower values while minute ventilation, the number of periodic breathing cycles and heart rate were higher (60%; 8.6 L/min; 97 cycles/h; 94 beats/min, respectively in subjects subsequently developing HAPE than in controls (73%; 5.1 L/min; 48 cycles/h; 79 beats/min; P<0.05 vs. HAPE, all instances. CONCLUSION: The results comprehensively represent the pattern of physiologic alterations that precede overt HAPE. The changes in lung function are consistent with reduced lung compliance and impaired gas exchange. Pronounced nocturnal hypoxemia, ventilatory control instability and sympathetic stimulation are further signs of subsequent overt HAPE.

  12. Altitude headache.

    Science.gov (United States)

    Lopez, J Ivan; Holdridge, Ashley; Mendizabal, Jorge E

    2013-12-01

    High altitude headache (HAH) has been defined by the International Headache Society as a headache that appears within 24 hours after ascent to 2,500 m or higher [1••]. The headache can appear in isolation or as part of acute mountain sickness (AMS), which has more dramatic symptoms than the headache alone. If symptoms are ignored, more serious conditions such as high altitude cerebral edema (HACE), high altitude pulmonary edema (HAPE), or even death may ensue. While there is no definitive understanding of the underlying pathophysiologic mechanism, it is speculated that HAH occurs from the combination of hypoxemia-induced intracranial vasodilation and subsequent cerebral edema. There are a number of preventive measures that can be adopted prior to ascending, including acclimatization and various medications. A variety of pharmacological interventions are also available to clinicians to treat this extremely widespread condition.

  13. Systems Design and Experimental Evaluation of a High-Altitude Relight Test Facility

    Science.gov (United States)

    Paxton, Brendan

    Novel advances in gas turbine engine combustor technology, led by endeavors into fuel efficiency and demanding environmental regulations, have been fraught with performance and safety concerns. While the majority of low emissions gas turbine engine combustor technology has been necessary for power generation applications, the push for ultra-low NOx combustion in aircraft jet engines has been ever present. Recent state-of-the-art combustor designs notably tackle historic emissions challenges by operating at fuel-lean conditions, which are characterized by an increase in the amount of air flow sent to the primary combustion zone. While beneficial in reducing NOx emissions, the fuel-lean mechanisms that characterize these combustor designs rely heavily upon high-energy and high-velocity air flows to sufficiently mix and atomize fuel droplets, ultimately leading to flame stability concerns during low-power operation. When operating at high-altitude conditions, these issues are further exacerbated by the presence of low ambient air pressures and temperatures, which can lead to engine flame-out situations and hamper engine relight attempts. To aid academic and industrial research ventures into improving the high-altitude lean blow-out and relight performance of modern gas turbine engine combustor technologies, the High-Altitude Relight Test Facility (HARTF) was designed and constructed at the University of Cincinnati (UC) Combustion and Fire Research Laboratory (CFRL). Following its construction, an experimental evaluation of its abilities to facilitate optically-accessible ignition, combustion, and spray testing for gas turbine engine combustor hardware at simulated high-altitude conditions was performed. In its evaluation, performance limit references were established through testing of the HARTF vacuum and cryogenic air-chilling capabilities. These tests were conducted with regard to end-user control---the creation and the maintenance of a realistic high-altitude

  14. Mammals of the high altitudes of western Arunachal Pradesh, eastern Himalaya: an assessment of threats and conservation needs

    NARCIS (Netherlands)

    Mishra, C.; Madhusudan, M.D.; Datta, A.

    2006-01-01

    he high altitudes of Arunachal Pradesh, India, located in the Eastern Himalaya biodiversity hotspot, remain zoologically unexplored and unprotected. We report results of recent mammal surveys in the high altitude habitats of western Arunachal Pradesh. A total of 35 mammal species (including 12 carni

  15. Mammals of the high altitudes of western Arunachal Pradesh, eastern Himalaya: an assessment of threats and conservation needs

    NARCIS (Netherlands)

    Mishra, C.; Madhusudan, M.D.; Datta, A.

    2006-01-01

    he high altitudes of Arunachal Pradesh, India, located in the Eastern Himalaya biodiversity hotspot, remain zoologically unexplored and unprotected. We report results of recent mammal surveys in the high altitude habitats of western Arunachal Pradesh. A total of 35 mammal species (including 12 carni

  16. Mammals of the high altitudes of western Arunachal Pradesh, eastern Himalaya: an assessment of threats and conservation needs

    NARCIS (Netherlands)

    Mishra, C.; Madhusudan, M.D.; Datta, A.

    2006-01-01

    he high altitudes of Arunachal Pradesh, India, located in the Eastern Himalaya biodiversity hotspot, remain zoologically unexplored and unprotected. We report results of recent mammal surveys in the high altitude habitats of western Arunachal Pradesh. A total of 35 mammal species (including 12

  17. Effect of reduced pressure, vibration and orientation to simulate high altitude testing of liquid pharmaceutical glass and plastic bottles

    NARCIS (Netherlands)

    Singh, S. Paul; Burgess, Gary; Kremer, Matt; Lockhart, Hugh

    2007-01-01

    This paper discusses the impact of high-altitude shipments of glass and plastic bottles on package integrity. High altitudes are encountered when trucks travel over mountain passes and when cargo and feeder aircraft transport packages in non-pressurized or partially pressurized cargo holds. This is

  18. Operating Water Cherenkov Detectors in high altitude sites for the Large Aperture GRB Observatory

    CERN Document Server

    Allard, D; Asorey, H; Barros, H; Bertou, X; Castillo, M; Chirinos, J M; De Castro, A; Flores, S; González, J; Berisso, M Gomez; Grajales, J; Guada, C; Day, W R Guevara; Ishitsuka, J; López, J A; Martínez, O; Melfo, A; Meza, E; Loza, P Miranda; Barbosa, E Moreno; Murrugarra, C; Núñez, L A; Ormachea, L J Otiniano; Pérez, G; Perez, Y; Ponce, E; Quispe, J; Quintero, C; Rivera, H; Rosales, M; Rovero, A C; Saavedra, O; Salazar, H; Tello, J C; Peralda, R Ticona; Varela, E; Velarde, A; Villaseñor, L; Wahl, D; Zamalloa, M A

    2009-01-01

    Water Cherenkov Detectors (WCD) are efficient detectors for detecting GRBs in the 10 GeV - 1 TeV energy range using the single particle technique, given their sensitivity to low energy secondary photons produced by high energy photons when cascading in the atmosphere. The Large Aperture GRB Observatory (LAGO) operates arrays of WCD in high altitude sites (above 4500 m a.s.l.) in Bolivia, Mexico and Venezuela, with planned extension to Peru. Details on the operation and stability of these WCD in remote sites with high background rates of particles will be detailed, and compared to simulations. Specific issues due to operation at high altitude, atmospheric effects and solar activity, as well as possible hardware enhancements will also be presented.

  19. Correlation of vascular endothelial growth factor to permeability of blood-brain barrier and brain edema during high-altitude exposure

    Institute of Scientific and Technical Information of China (English)

    Qiquan Zhou; Chang'e Liu; Jing Wang; Yunli Wang; Bo Zhou

    2009-01-01

    BACKGROUND:Many studies have evaluated the role of vascular endothelial growth factor (VEGF) in traumatic brain edema and hemorrhagic brain edema.OBJECTIVE:To observe the effects of VEGF expression on permeability of the blood-brain barrier (BBB) during high-altitude and hypoxia exposure,and to investigate the correlation between VEGF expression and BBB permeability with regard to Evans blue staining and brain edema during high-altitude exposure.DESIGN,TIME AND SETTING:The randomized,controlled,animal study was performed at the Tanggula Etape,Central Laboratory of Chengdu Medical College,and Central Laboratory of General Hospital of Chengdu Military Area Command of Chinese PLA,China,from July 2003 to November 2004.MATERIALS:Quantitative RT-PCR kit (Sigma,USA),VEGF ELISA kit (Biosource,USA),and Evans blue (Jingchun,China) were acquired for this study.METHODS:A total of 180 Wistar rats were equally and randomly assigned to 15 groups:low-altitude (500 m),middle-altitude (2 880 m),high-altitude (4 200 m),super-high-altitude (5 000 m),1,3,5,7,9,11,13,15,17,19,and 21 days of super high-altitude exposure.Wistar rats were exposed to various altitude gradients to establish a hypoxia model.MAIN OUTCOME MEASURES:Brain water content was calculated according to the wet-to-dry weight ratio.BBB permeability to Evans blue was determined by colorimetric method.VEGF mRNA and protein levels in brain tissues were detected using RT-PCR and double-antibody sandwich ELISA.RESULTS:Brain water content,BBB permeability to Evans blue,and VEGF mRNA and protein levels in brain tissues increased with increasing altitude and prolonged exposure to altitude.The greatest increase was determined on day 9 upon ascending 5 000 m.Simultaneously,VEGF expression positively correlated to BBB permeability of Evans blue and brain water content (r=0.975,0.917,P<0.01).CONCLUSION:Increased VEGF protein and mRNA expression was responsible for increased BBB permeability,which may be an important mechanism

  20. Limnology and cyanobacterial diversity of high altitude lakes of Lahaul-Spiti in Himachal Pradesh, India.

    Science.gov (United States)

    Singh, Y; Khattar, Jis; Singh, D P; Rahi, P; Gulati, A

    2014-09-01

    Limnological data of four high altitude lakes from the cold desert region of Himachal Pradesh, India, has been correlated with cyanobacterial diversity. Physico-chemical characteristics and nutrient contents of the studied lakes revealed that Sissu Lake is mesotrophic while Chandra Tal, Suraj Tal and Deepak Tal are ultra-oligotrophic. Based on morphology and 16S rRNA gene sequence, a total of 20 cyanobacterial species belonging to 11 genera were identified. Canonical correspondence analysis distinguished three groups of species with respect to their occurrence and nutrient/physical environment demand. The first group, which included Nostoc linckia, N. punctiforme, Nodularia sphaerocarpa, Geitlerinema acutissimum, Limnothrix redekii, Planktothrix agardhii and Plank. clathrata, was characteristic of water with high nutrient content and high temperature. The second group, including Gloeocapsopsis pleurocapsoides, Leptolyngbya antarctica, L. frigida, Pseudanabaena frigida and N. spongiaeforme, occurred in oligotrophic water with high pH and low temperature. The distribution of third group of Cyanobium parvum, Synechocystis pevalekii, L. benthonica, L. foveolarum, L. lurida, L. valderiana, Phormidium autumnale and P. chalybeum could not be associated with a particular environmental condition because of their presence in all sampling sites.

  1. Limnology and cyanobacterial diversity of high altitude lakes of Lahaul-Spiti in Himachal Pradesh, India

    Indian Academy of Sciences (India)

    Y Singh; J I S Khattar; D P Singh; P Rahi; A Gulati

    2014-09-01

    Limnological data of four high altitude lakes from the cold desert region of Himachal Pradesh, India, has been correlated with cyanobacterial diversity. Physico-chemical characteristics and nutrient contents of the studied lakes revealed that Sissu Lake is mesotrophic while Chandra Tal, Suraj Tal and Deepak Tal are ultra-oligotrophic. Based on morphology and 16S rRNA gene sequence, a total of 20 cyanobacterial species belonging to 11 genera were identified. Canonical correspondence analysis distinguished three groups of species with respect to their occurrence and nutrient/physical environment demand. The first group, which included Nostoc linckia, N. punctiforme, Nodularia sphaerocarpa, Geitlerinema acutissimum, Limnothrix redekii, Planktothrix agardhii and Plank. clathrata, was characteristic of water with high nutrient content and high temperature. The second group, including Gloeocapsopsis pleurocapsoides, Leptolyngbya antarctica, L. frigida, Pseudanabaena frigida and N. spongiaeforme, occurred in oligotrophic water with high pH and low temperature. The distribution of third group of Cyanobium parvum, Synechocystis pevalekii, L. benthonica, L. foveolarum, L. lurida, L. valderiana, Phormidium autumnale and P. chalybeum could not be associated with a particular environmental condition because of their presence in all sampling sites.

  2. Elemental stoichiometry indicates predominant influence of potassium and phosphorus limitation on arbuscular mycorrhizal symbiosis in acidic soil at high altitude.

    Science.gov (United States)

    Khan, Mohammad Haneef; Meghvansi, Mukesh K; Gupta, Rajeev; Veer, Vijay

    2015-09-15

    The functioning of high-altitude agro-ecosystems is constrained by the harsh environmental conditions, such as low temperatures, acidic soil, and low nutrient supply. It is therefore imperative to investigate the site-specific ecological stoichiometry with respect to AM symbiosis in order to maximize the arbuscular mycorrhizal (AM) benefits for the plants in such ecosystems. Here, we assess the elemental stoichiometry of four Capsicum genotypes grown on acidic soil at high altitude in Arunachal Pradesh, India. Further, we try to identify the predominant resource limitations influencing the symbioses of different Capsicum genotypes with the AM fungi. Foliar and soil elemental stoichiometric relations of Capsicum genotypes were evaluated with arbuscular mycorrhizal (AM) colonization and occurrence under field conditions. AM fungal diversity in rhizosphere, was estimated through PCR-DGGE profiling. Results demonstrated that the symbiotic interaction of various Capsicum genotypes with the AM fungi in acidic soil was not prominent in the study site as evident from the low range of root colonization (21-43.67%). In addition, despite the rich availability of carbon in plant leaves as well as in soil, the carbon-for-phosphorus trade between AMF and plants appeared to be limited. Our results provide strong evidences of predominant influence of the potassium-limitation, in addition to phosphorus-limitation, on AM symbiosis with Capsicum in acidic soil at high altitude. We also conclude that the potassium should be considered in addition to carbon, nitrogen, and phosphorus in further studies investigating the stoichiometric relationships with the AMF symbioses in high altitude agro-ecosystems.

  3. Grappling the High Altitude for Safe Edible Bamboo Shoots with Rich Nutritional Attributes and Escaping Cyanogenic Toxicity

    Directory of Open Access Journals (Sweden)

    Sayanika Devi Waikhom

    2013-01-01

    Full Text Available Consumption of bamboo species with high level of total cyanogenic content (TCC in Asia by many ethnic groups is significantly associated with food poisoning and occasionally Konzo (a neurological disorder. Adequate characterization of edible bamboo species with low level of TCC and high nutritious attributes is required for consumer’s safety as well as for the conservation of the gene pool. Here, we employed morphological descriptors, atomic absorption spectrophotometer, RAPD, and trnL-F intergenic spacer to characterize 15 indigenous edible bamboo species of north-east India. The study indicates that morphologically and genetically evolved edible bamboo species having large and robust bamboo-shoot texture and growing at low altitude contain high level of TCC, low antioxidant properties, and low levels of beneficial macronutrients and micronutrients. Importantly, Dendrocalamus species are shown to be rich in TCC irrespective of the growing altitude while Bambusa species are found to have moderate level of TCC. The findings clearly demonstrated that Chimonobambusa callosa growing at high altitude represents safe edible bamboo species with nutritious attributes.

  4. High-Altitude Aircraft-Based Electric-Field Measurements Above Thunderstorms

    Science.gov (United States)

    Bateman, M. G.; Blakeslee, R. J.; Bailey, J. C.; Stewart, M. F.; Blair, A. K.

    1999-01-01

    We have developed a new set of eight electric field mills that were flown on a NASA ER-2 high-altitude aircraft. During the Third Convection And Moisture EXperiment (CAMEX-3; Fall, 1998), measurements of electric field, storm dynamics, and ice microphysics were made over several hurricanes. Concurrently, the TExas-FLorida UNderflights (TEFLUN) program was being conducted to make the same measurements over Gulf Coast thunderstorms. Sample measurements are shown: typical flight altitude is 20km. Our new mills have an internal 16-bit A/D, with a resolution of 0.25V/m per bit at high gain, with a noise level less than the least significant bit. A second, lower gain channel gives us the ability to measure fields as high as 150 kV/m.

  5. Dementia in a tribal landlocked elderly population at high altitude: What explains the lower prevalence?

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Raina

    2016-01-01

    Full Text Available Introduction: Studies across the populations have suggested that dementia is differentially distributed with a lower prevalence in developing regions than the developed ones. A comparison in the prevalence of dementia across populations may provide an insight into its risk factors. Earlier, we reported on the prevalence of dementia in elderly population in migrant, urban, rural, and tribal populations. The present study was conducted with a view to estimating the prevalence of dementia in Tribal Landlocked Elderly Population at high altitude and therefore to draw some conclusions on the differential distribution of dementia across populations. Methods: A cross-sectional comprehensive two-phase survey of all residents aged 60 years and older was conducted. Phase 1 involved screening of all individuals aged 60 and above with the help of a cognitive screen specifically developed for the tribal population. Phase 2 involved clinical examination of individuals who were suspected of dementia as per the developed cognitive screening test. Results: The results revealed that six individuals out of a total of 481 studied above 60 years of age in the studied population scored between 17 and 23, thus qualifying as suffering from mild cognitive impairment. Importantly, none of the individuals above 60 years of age scored <17. Discussion: The current study is in conformity with our previous study conducted on urban, rural, and migrant areas of the state of Himachal Pradesh again emphasizing on dementia being rare in tribal populations and thereby pointing to the presence of some protective factors among tribal people.

  6. Cosmic Ray Astrophysics using The High Altitude Water Cherenkov (HAWC Observatory in México

    Directory of Open Access Journals (Sweden)

    de la Fuente Eduardo

    2017-01-01

    Full Text Available The High-Altitude Water Cherenkov (HAWC TeV gamma–ray Observatory in México is ready to search and study gamma-ray emission regions, extremely high-energy cosmic-ray sources, and to identify transient phenomena. With a better Gamma/Hadron rejection method than other similar experiments, it will play a key role in triggering multi–wavelength and multi–messenger studies of active galaxies (AGN, gamma-ray bursts (GRB, supernova remnants (SNR, pulsar wind nebulae (PWN, Galactic Plane Sources, and Cosmic Ray Anisotropies. It has an instantaneous field-of-view of ∼2 str, equivalent to 15% of the whole sky and continuous operation (24 hours per day. The results obtained by HAWC–111 (111 detectors in operation were presented on the proceedings of the International Cosmic Ray Conference 2015 and in [1]. The results obtained by HAWC–300 (full operation are now under analysis and will be published in forthcoming papers starting in 2017 (see preliminary results on http://www.hawc-observatory.org/news/. Here we present the HAWC contributions on cosmic ray astrophysics via anisotropies studies, summarizing the HAWC detector and its upgrading by the installation of “outriggers”.

  7. Analysis of the Hybrid Power System for High-Altitude Unmanned Aircraft

    Directory of Open Access Journals (Sweden)

    Kangwen Sun

    2015-01-01

    Full Text Available The application of single solar array on high-altitude unmanned aircraft will waste energy because of its low conversion efficiency. Furthermore, since its energy utilization is limited, the surface temperature of solar array will rise to 70°C due to the waste solar energy, thus reducing the electrical performance of the solar array. In order to reuse the energy converted into heat by solar array, a hybrid power system is presented in this paper. In the hybrid power system, a new electricity-generating method is adopted to spread the photovoltaic cell on the wing surface and arrange photothermal power in the wing box section. Because the temperature on the back of photovoltaic cell is high, it can be used as the high-temperature heat source. The lower wing surface can be a low-temperature cold source. A high-altitude unmanned aircraft was used to analyze the performances of pure solar-powered aircraft and hybrid powered aircraft. The analysis result showed that the hybrid system could reduce the area of wing by 19% and that high-altitude unmanned aircraft with a 35 m or less wingspan could raise the utilization rate of solar energy per unit area after adopting the hybrid power system.

  8. Red Maca (Lepidium meyenii), a Plant from the Peruvian Highlands, Promotes Skin Wound Healing at Sea Level and at High Altitude in Adult Male Mice.

    Science.gov (United States)

    Nuñez, Denisse; Olavegoya, Paola; Gonzales, Gustavo F; Gonzales-Castañeda, Cynthia

    2017-08-28

    Nuñez, Denisse, Paola Olavegoya, Gustavo F. Gonzales, and Cynthia Gonzales-Castañeda. Red maca (Lepidium meyenii), a plant from the Peruvian highlands, promotes skin wound healing at sea level and at high altitude in adult male mice. High Alt Med Biol 00:000-000, 2015.-Wound healing consists of three simultaneous phases: inflammation, proliferation, and remodeling. Previous studies suggest that there is a delay in the healing process in high altitude, mainly due to alterations in the inflammatory phase. Maca (Lepidium meyenii) is a Peruvian plant with diverse biological properties, such as the ability to protect the skin from inflammatory lesions caused by ultraviolet radiation, as well as its antioxidant and immunomodulatory properties. The aim of this study was to determine the effect of high altitude on tissue repair and the effect of the topical administration of the spray-dried extract of red maca (RM) in tissue repair. Studies were conducted in male Balb/c mice at sea level and high altitude. Lesions were inflicted through a 10 mm-diameter excisional wound in the skin dorsal surface. Treatments consisted of either (1) spray-dried RM extract or (2) vehicle (VH). Animals wounded at high altitude had a delayed healing rate and an increased wound width compared with those at sea level. Moreover, wounding at high altitude was associated with an increase in inflammatory cells. Treatment with RM accelerated wound closure, decreased the level of epidermal hyperplasia, and decreased the number of inflammatory cells at the wound site. In conclusion, RM at high altitude generate a positive effect on wound healing, decreasing the number of neutrophils and increasing the number of macrophages in the wound healing at day 7 postwounding. This phenomenon is not observed at sea level.

  9. Pulmonary gas exchange at maximal exercise in Danish lowlanders during 8 wk of acclimatization to 4,100 m and in high-altitude Aymara natives

    DEFF Research Database (Denmark)

    Lundby, Carsten; Calbet, Jose A L; van Hall, Gerrit

    2004-01-01

    We aimed to test effects of altitude acclimatization on pulmonary gas exchange at maximal exercise. Six lowlanders were studied at sea level, in acute hypoxia (AH), and after 2 and 8 wk of acclimatization to 4,100 m (2W and 8W) and compared with Aymara high-altitude natives residing at this altit......We aimed to test effects of altitude acclimatization on pulmonary gas exchange at maximal exercise. Six lowlanders were studied at sea level, in acute hypoxia (AH), and after 2 and 8 wk of acclimatization to 4,100 m (2W and 8W) and compared with Aymara high-altitude natives residing...... at this altitude. As expected, alveolar Po2 was reduced during AH but increased gradually during acclimatization (61 +/- 0.7, 69 +/- 0.9, and 72 +/- 1.4 mmHg in AH, 2W, and 8W, respectively), reaching values significantly higher than in Aymaras (67 +/- 0.6 mmHg). Arterial Po2 (PaO2) also decreased during exercise...... in AH but increased significantly with acclimatization (51 +/- 1.1, 58 +/- 1.7, and 62 +/- 1.6 mmHg in AH, 2W, and 8W, respectively). PaO2 in lowlanders reached levels that were not different from those in high-altitude natives (66 +/- 1.2 mmHg). Arterial O2 saturation (SaO2) decreased during maximum...

  10. Shared and unique signals of high-altitude adaptation in geographically distinct Tibetan populations.

    Directory of Open Access Journals (Sweden)

    Tana Wuren

    Full Text Available Recent studies have used a variety of analytical methods to identify genes targeted by selection in high-altitude populations located throughout the Tibetan Plateau. Despite differences in analytic strategies and sample location, hypoxia-related genes, including EPAS1 and EGLN1, were identified in multiple studies. By applying the same analytic methods to genome-wide SNP information used in our previous study of a Tibetan population (n = 31 from the township of Maduo, located in the northeastern corner of the Qinghai-Tibetan Plateau (4200 m, we have identified common targets of natural selection in a second geographically and linguistically distinct Tibetan population (n = 46 in the Tuo Tuo River township (4500 m. Our analyses provide evidence for natural selection based on iHS and XP-EHH signals in both populations at the p<0.02 significance level for EPAS1, EGLN1, HMOX2, and CYP17A1 and for PKLR, HFE, and HBB and HBG2, which have also been reported in other studies. We highlight differences (i.e., stratification and admixture in the two distinct Tibetan groups examined here and report selection candidate genes common to both groups. These findings should be considered in the prioritization of selection candidate genes in future genetic studies in Tibet.

  11. Observations with the High Altitude GAmma Ray (HAGAR) telescope array in the Indian Himalayas

    Science.gov (United States)

    Britto, R. J.; Acharya, B. S.; Anupama, G. C.; Bhatt, N.; Bhattacharjee, P.; Bhattacharya, S. S.; Chitnis, V. R.; Cowsik, R.; Dorji, N.; Duhan, S. K.; Gothe, K. S.; Kamath, P. U.; Koul, R.; Mahesh, P. K.; Mitra, A.; Nagesh, B. K.; Parmar, N. K.; Prabhu, T. P.; Rannot, R. C.; Rao, S. K.; Saha, L.; Saleem, F.; Saxena, A. K.; Sharma, S. K.; Shukla, A.; Singh, B. B.; Srinivasan, R.; Srinivasulu, G.; Sudersanan, P. V.; Tickoo, A. K.; Tsewang, D.; Upadhya, S.; Vishwanath, P. R.; Yadav, K. K.

    2010-12-01

    For several decades, it was thought that astrophysical sources emit high energy photons within the energy range of the gamma-ray region of the electromagnetic spectrum also. These photons originate from interactions of high energy particles from sources involving violent phenomena in the Universe (supernovae, pulsars, Active Galactic Nuclei, etc.) with gas and radiation fields. Since the first reliable detections of cosmic gamma rays in the 1970's, improvements in instrumentation have led gamma-ray astronomy to an established branch of modern Astrophysics, with a constant increase in the number of detected sources. But the 30-300 GeV energy range remained sparsely explored until the launch of the Fermi space telescope in June 2008. The ground-based gamma-ray telescope array HAGAR is the first array of atmospheric Cherenkov telescopes established at a so high altitude (4270 m a.s.l.), and was designed to reach a relatively low energy threshold with quite a low mirror area (31 m^2). It is located at Hanle in India, in the Ladakh region of the Himalayas. Regular source observations have begun with the complete setup of 7 telescopes on Sept. 2008. We report and discuss our estimation of the systematics through dark region studies, and present preliminary results from gamma-ray sources in this paper.

  12. Changes of autonomic nervous system function in healthy young men during initial phase at acute high-altitude exposure

    Institute of Scientific and Technical Information of China (English)

    Qin Jun; Huang Lan; Tian Kaixin; Yu Shiyong; Yu Yang; Long Min

    2008-01-01

    Objective: To investigate the changes of autonomic nervous system (ANS) function during the initial phase at acute high-altitude exposure. Methods: Ninety-nine healthy sea-level male residents were studied in Chengdu plain and then Tibet plateau. Heart rate variability (HRV), cold pressor test (CPT), resting heart rate (HR) and blood pressure (BP) were measured at baseline (560 m altitude) and in 2 to 4 d after arriving at Tibet plateau (3 675 m altitude) to assess the ANS function. Results: Compared with baseline, on day 2 in Tibet the standard deviation of normal to normal intervals (SDNN), high-frequency (HF) power, total power (TP), root mean square of delta RR (rMSSD), percentage of delta RR>50 ms (PNN50), normalized high-frequency (Hfnu) and fractal dimension (FD) decreased significantly (SDNN, HF,TP P<0.01, rMSSD, PNNs0, Hfnu, FD P<0.05), while the normalized low-frequency (Lfnu) and LF/HF increased significantly (P<0.01). During day 3-4 in Tibet, SDNN, rMSSD, HF, TP and Hfnu tended to rebound while Lfnu and LF/HF decreased towards baseline day by day. In addition, in Tibet the increase in systolic pressure (SP) and diastolic pressure (DP) during CPT decreased significantly (P<0.01, 0.05), but resting HR increased compared with baseline (P<0.01). Conclusion: ANS modulation is generally blunted, and the relatively predominant sympathetic control is enhanced originally, then it reverts to the sea level states gradually during the initial days of acute high-altitude exposure.

  13. Dirrofilariasis in Shepherd Dogs of High Altitudes Areas in West Azerbaijan-Iran

    Directory of Open Access Journals (Sweden)

    Mojtaba Hadian

    2011-03-01

    Full Text Available Although the biology and ecology of the arthropod vectors are different, some factors, such as global warming, the increasing abundance of mosquitoes, the movement of domestic hosts, and the abundance of wild reservoirs, can act as favourable factors for the distribution of infections. The aim of this study was to determine the prevalence of Dirofilaria immitis infection in shepherd dogs living in the high altitude of mountainous area (i.e.1200 meters above the sea level. The study group was comprised of 160 shepherd dogs living in 4 mountainous regions (Targavar, Margavar, Kolshin and Hovarchin of west Azerbaijan where continuous movement of sheep and goat flocks resulted to have a little information about shepherd dogs in these regions. Additionally, arduous pathways have made impossible any access by car to some territories of these areas. The dogs were mostly mixed raced with different ages (from 1 to 10 years and sexes (male = 136, female = 24. Blood samples were collected from cephalic vein. Direct thin and thick blood smears and modified knott’s technique were used for detecting D.immitis microfilariae and other blood parasites. The results indicated that 40 (25 % of dogs were infected with D. immitis microfilariae. In examination of the dogs, no severe life threatening feature of the disease was diagnosed. There were no significant differences (P > 0.05 of Dirrofilaria infection among gender, age groups and geographical areas. High prevalence of asymptomatic Dirrofilariasis in shepherd dogs in this area highlights the need of controlling and preventive programs.

  14. Discovery of C4 species at high altitude in Qinghai-Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    WANG Luo; L(U) Houyuan; WU Naiqin; CHU Duo; HAN Jiamao; WU Yuhu; WU Haibin; GU Zhaoyan

    2004-01-01

    Plant specimens are collected from the areas between latitude 27°42'N and 40°57'N, and longitude 88°93'E and 103°24'E, with an altitudinal range from 2210 to 5050 m above the sea level in Qinghai-Tibetan Plateau. The stable carbon isotope analysis indicates that two of Chenopodiaceae and six of Poaceae in the samples are C4 plants. Four of the C4 plants are found in 11 spots with altitudes above 3800 m,and Pennisetum centrasiaticum, Arundinella yunnanensis and Orinus thoroldii are present in six spots above 4000 m, even up to 4520 m. At low CO2 partial pressure, that sufficient energy of high light improving C4 plant's tolerance of low temperature and precipitations concentrating in growing season probably are favorable for C4 plants growing at high altitude in Qinghai-Tibetan Plateau.

  15. Contribution of Neutron Beta Decay to Radiation Belt Pumping from High Altitude Nuclear Explosion

    Energy Technology Data Exchange (ETDEWEB)

    Marrs, R

    2002-11-13

    In 1962, several satellites were lost following high altitude nuclear tests by the United States and the Soviet Union. These satellite failures were caused by energetic electrons injected into the earth's radiation belts from the beta decay of bomb produced fission fragments and neutrons. It has been 40 years since the last high altitude nuclear test; there are now many more satellites in orbit, and it is important to understand their vulnerability to radiation belt pumping from nuclear explosions at high altitude or in space. This report presents the results of a calculation of the contribution of neutron beta decay to artificial belt pumping. For most high altitude nuclear explosions, neutrons are expected to make a smaller contribution than fission products to the total trapped electron inventory, and their contribution is usually neglected. However, the neutron contribution may dominate in cases where the fission product contribution is suppressed due to the altitude or geomagnetic latitude of the nuclear explosion, and for regions of the radiation belts with field lines far from the detonation point. In any case, an accurate model of belt pumping from high altitude nuclear explosions, and a self-consistent explanation of the 1962 data, require inclusion of the neutron contribution. One recent analysis of satellite measurements of electron flux from the 1962 tests found that a better fit to the data is obtained if the neutron contribution to the trapped electron inventory was larger than that of the fission products [l]. Belt pumping from high altitude nuclear explosions is a complicated process. Fission fragments are dispersed as part of the ionized bomb debris, which is constrained and guided by the earth's magnetic field. Those fission products that beta decay before being lost to the earth's atmosphere can contribute trapped energetic electrons to the earth's radiation belts. There has been a large effort to develop computer models for

  16. Feasibility of Laser Power Transmission to a High-Altitude Unmanned Aerial Vehicle

    Science.gov (United States)

    2011-01-01

    possible to imagine the laser beam arriving at the UAV from above, perhaps bounced down from a satel- lite or airship , but this seems like an excessive...thus lending themselves to applica- tion on the aerodynamic surfaces of a UAV. InGaAs cells can also be used to convert laser light at longer wavelengths...Design and Predictions for a High-Altitude (Low- Reynolds-Number) Aerodynamic Flight Experiment, Edwards Air Force Base, Calif.: NASA Dryden Flight

  17. America’s Achilles Heel: Defense Against High-altitude Electromagnetic Pulse-policy vs. Practice

    Science.gov (United States)

    2014-12-12

    Energy Regulatory Commission FM Field Manual GRID Act Grid Reliability and Infrastructure Defense Act HEMP High-Altitude Electromagnetic Pulse JP...product to the end user.41 Across the U.S., there are upwards of 40,000 miles of gathering lines from the oil wells, both on and offshore , that feed into...particles are emitted at nearly the speed of light. The emissions can cause disturbances in the solar wind that disrupt satellites and create powerful

  18. Genetic variants in EPAS1 contribute to adaptation to high-altitude hypoxia in Sherpas.

    Directory of Open Access Journals (Sweden)

    Masayuki Hanaoka

    Full Text Available Sherpas comprise a population of Tibetan ancestry in the Himalayan region that is renowned for its mountaineering prowess. The very small amount of available genetic information for Sherpas is insufficient to explain their physiological ability to adapt to high-altitude hypoxia. Recent genetic evidence has indicated that natural selection on the endothelial PAS domain protein 1 (EPAS1 gene was occurred in the Tibetan population during their occupation in the Tibetan Plateau for millennia. Tibetan-specific variations in EPAS1 may regulate the physiological responses to high-altitude hypoxia via a hypoxia-inducible transcription factor pathway. We examined three significant tag single-nucleotide polymorphisms (SNPs, rs13419896, rs4953354, and rs4953388 in the EPAS1 gene in Sherpas, and compared these variants with Tibetan highlanders on the Tibetan Plateau as well as with non-Sherpa lowlanders. We found that Sherpas and Tibetans on the Tibetan Plateau exhibit similar patterns in three EPAS1 significant tag SNPs, but these patterns are the reverse of those in non-Sherpa lowlanders. The three SNPs were in strong linkage in Sherpas, but in weak linkage in non-Sherpas. Importantly, the haplotype structured by the Sherpa-dominant alleles was present in Sherpas but rarely present in non-Sherpas. Surprisingly, the average level of serum erythropoietin in Sherpas at 3440 m was equal to that in non-Sherpas at 1300 m, indicating a resistant response of erythropoietin to high-altitude hypoxia in Sherpas. These observations strongly suggest that EPAS1 is under selection for adaptation to the high-altitude life of Tibetan populations, including Sherpas. Understanding of the mechanism of hypoxia tolerance in Tibetans is expected to provide lights to the therapeutic solutions of some hypoxia-related human diseases, such as cardiovascular disease and cancer.

  19. On the HEMP (high-altitude electromagnetic pulse) environment for protective relays

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, D.E.; Wiggins, C.M.; Salas, T.M. (BDM International, Inc., Albuquerque, NM (USA)); Barnes, P.R. (Oak Ridge National Lab., TN (USA))

    1990-01-01

    An assessment of the transient environment for protective relays produced by high-altitude electromagnetic pulse (HEMP) events is presented in this paper. Several mechanisms for coupling of HEMP to relay terminals are used to develop estimates of possible HEMP threats to relays. These predicted relay responses to HEMP events are compared to measured data on a solid state based relay's impulse strength. 12 refs., 13 figs., 3 tabs.

  20. Using isotope, hydrochemical methods and energy-balance modelling to estimate contribution of different components to flow forming process in a high-altitude catchment (Dzhancuat river basin case study)

    Science.gov (United States)

    Rets, Ekaterina; Loshakova, Nadezhda; Chizhova, Julia; Kireeva, Maria; Frolova, Natalia; Tokarev, Igor; Budantseva, Nadine; Vasilchuk, Yurij

    2016-04-01

    A multicomponent structure of sources of river runoff formation is characteristic of high-altitude territories: ice and firn melting; seasonal snow melting on glacier covered and non-glacier area of a watershed; liquid precipitation; underground waters. In addition, each of these components can run off the watershed surface in different ways. Use of isotopic, hydrochemical methods and energy balance modelling provides possibility to estimate contribution of different components to river runoff that is an essential to understand the mechanism of flow formation in mountainious areas. A study was carried out for Dzhancuat river basin that was chosen as representative for North Caucasus in course of the International Hydrological Decade. Complex glaciological, hydrological and meteorological observation have been carried in the basin since 1965. In years 2013-2015 the program also included daily collecting of water samples on natural stable isotopes on the Dzhancuat river gauging station, and sampling water nourishment sources (ice, snow, firn, liquid precipitation) within the study area. More then 800 water samples were collected. Application of an energy balance model of snow and ice melt with distributed parameters provided an opportunity to identify Dzhancuat river runoff respond to glaciers melt regime and seasonal redistribution of melt water. The diurnal amplitude of oscillation of the Dzhakuat river runoff in the days without precipitation is formed by melting at almost snow-free areas of the Dzhancuat glacier tongues. Snowmelt water from the non-glacierized part contributes to the formation of the next day runoff. A wave of snow and firn melt in upper zones of glacier flattens considerably during filtration through snow and run-off over the surface and in the body of the glacier. This determines a general significant inertia of the Dzhacuat river runoff. Some part of melt water is stored into natural regulating reservoirs of the watershed that supply the

  1. [Ecological study of Pyroglyphides mites in house dust in the Grenoble area. A qualitative approach and incidence of various parameters: seasons, altitude, temperature and relative dampness in their multiplication].

    Science.gov (United States)

    Lascaud, D

    1978-01-01

    This study concerns the analysis of 70 samples of dust mites taken periodically from 13 sample areas or mattresses at different altitudes. It shows the presence of Pyroglyphid mites in all the mattresses studied. Four species were found: Dermatophagoides pteronyssinus, Dermatophagoides farinae, Euroglyphus maynei and Dermatophagoides evansi. From a quantitative point of view, the statistical analysis of the results obtained allows the following conclusions to be drawn: -- All the Pyroglyphids (adults and young) undergo seasonal fluctuations at low, middle and high altitude. In the plains and at middle altitude these mites have a seasonal maximum and minimum. At high altitude only the seasonal maximum can be determined. -- The number of Pyroglyphids found is much higher in the plaine than at middle altitude and at middle altitude than at high altitude. The influence of altitude can be demonstrated with certitude. -- The conditions of temperature and relative dampness most favourable to the multiplication of mites are found in the plaine. At middle and high altitude these conditions are only met in summer. In flat country the statistical analysis allows us to show the existance of a correlation between the rate of dampness and the number of Pyroglyphids, and more specially, between the dampness rate and Dermatophagoides farinae, a predominant species at this sampling area. At middle and high altitude such a correlation cannot be shown clearly. At the three altitudes considered, no correlation can be established between the temperature and the number of Pyroglyphid mites found.

  2. Niche segregation in high-altitude Himalayan chats (Aves, Turdidae): does morphology match ecology?

    Science.gov (United States)

    Landmann, Armin; Winding, Norbert

    1993-10-01

    We investigated patterns of habitat segregation and morphological differentiation in syntopic, closely related turdid birds of the alpine zone of the Central Himalayas. Discriminant function analysis of 19 habitat structure parameters and comparisons of additional habitat features revealed that the species were distributed along gradients of vegetation height and vegetation density. In addition, non-vegetational structural habitat features, like microrelief variability or the presence of rocks and boulders, had strong discriminating power. In terms of habitat preferences the species of the guild investigated formed three subsets: shrubbery species (Erithacus pectoralis, E. chrysaeus and Hodgsonius phoenicuroides), species preferring open areas with higher surface roughness (Phoenicurus frontalis, Chaimarrornis leucocephalus) and the high-altitude species Grandala coelicolor. Using discriminant function analysis of 20 characters, morphology was analysed in relation to microhabitat utilization and foraging behaviour. Species inhabiting patches of shrubby thickets and foraging mainly by pedal movements (E. pectoralis, E. chrysaeus and H. phoenicuroides) have in common short rounded wings with high wing loading and strong legs and feet. Species preferably foraging by aerial hawking or "perch and pounce" techniques in more open areas (P. frontalis, C. chaimarrornis, and to some extent E. cyanurus) have longer wings, shorter tarsi and long rictal bristles. Grandala proved to be well adpated for long-distance flights at high altitudes (long, pointed wings) and for pedal foraging. Overall our results fit the basic assumption of ecomorphological theory that morphological distance reflects ecological distance. The ordination of each species in morphological space closely matched its distribution in ecological space (microhabitat, foraging strategies). Striking associations of morphology with ecology were not only evident for single traits but were also found in

  3. The Kilimanjaro score for assessing fitness to fly paragliders at high altitude.

    Science.gov (United States)

    Wilkes, Matt; Simpson, Alistair; Knox, Matt; Summers, Luke

    2013-09-01

    Extreme sports such as paragliding are increasing in popularity, providing continued challenges for the development of safe practice techniques. In January and February 2013, the Wings of Kilimanjaro expedition aimed to launch 95 paragliders from the summit of Mount Kilimanjaro, 5790 m above sea level. A safe launch was paramount but risked being impaired by adverse environmental conditions, in particular the pathophysiological effects of high altitude. There are no existing scores to assess fitness for high-altitude paraglider launches present in the literature. A novel scoring system, the Kilimanjaro Score, was therefore developed to rapidly assess pilots pre-flight. The Kilimanjaro Score aimed to assess cognition, memory, and visual-spatial skill within the context of standard pre-flight checks. Further testing, including the Lake Louise Score, was to be performed if the pilot's Kilimanjaro Score was deemed unsatisfactory. We present the Kilimanjaro Score here for comment and refinement, and we invite other parties to consider its use in the field for high altitude paragliding activities.

  4. Combining Undergraduate Student Curriculum, Research, and Outreach: High-altitude Balloon and Rockets

    Science.gov (United States)

    Davis, E. J.; Nielsen, K.

    2015-12-01

    The Society of Physics Students chapter at Utah Valley University (UVU) recently established a high altitude balloon project to provide students with research opportunities. This highly successful program involves students not only from physics but also from other STEM fields and non-STEM subjects, and as such acts as a unique outreach program for the department of physics. Examples of experiments performed with the balloon project are: 3D-acceleration measurements, altitude/pressure/temperature measurements, ozone monitoring, bio-aerosol collection, and solar panel performance output. All these experiment are designed and build by groups of students either as part of research projects or through class participation as the projects link with the curriculum in several courses. Most recently, a group of UVU students have initiated the implementation of small rockets capable of carrying payloads to this high-altitude program. Both balloon and rocket platforms are fundamental in-situ measuring techniques for numerous geoscience subjects, and are arguably best illustrated by the NASA balloon and sounding rocket programs. In this presentation, we give an overview of the program and how it is 1) being implemented into the curriculum, 2) provide unique research opportunities for students, and 3) specific outreach activities.

  5. High Altitude Long Endurance UAV Analysis of Alternatives and Technology Requirements Development

    Science.gov (United States)

    Nickol, Craig L.; Guynn, Mark D.; Kohout, Lisa L.; Ozoroski, Thomas A.

    2007-01-01

    An Analysis of Alternatives and a Technology Requirements Study were conducted for two mission areas utilizing various types of High Altitude Long Endurance (HALE) Unmanned Aerial Vehicles (UAV). A hurricane science mission and a communications relay mission provided air vehicle requirements which were used to derive sixteen potential HALE UAV configurations, including heavier-than-air (HTA) and lighter-than-air (LTA) concepts with both consumable fuel and solar regenerative propulsion systems. A HTA diesel-fueled wing-body-tail configuration emerged as the preferred concept given near-term technology constraints. The cost effectiveness analysis showed that simply maximizing vehicle endurance can be a sub-optimum system solution. In addition, the HTA solar regenerative configuration was utilized to perform both a mission requirements study and a technology development study. Given near-term technology constraints, the solar regenerative powered vehicle was limited to operations during the long days and short nights at higher latitudes during the summer months. Technology improvements are required in energy storage system specific energy and solar cell efficiency, along with airframe drag and mass reductions to enable the solar regenerative vehicle to meet the full mission requirements.

  6. Origin of the turbulent spectra in the high-altitude cusp: Cluster spacecraft observations

    Directory of Open Access Journals (Sweden)

    K. Nykyri

    2006-05-01

    Full Text Available High-resolution magnetic field data from Cluster Flux Gate Magnetometer (FGM and the Spatio-Temporal Analysis of Field Fluctuations (STAFF instruments are used to study turbulent magnetic field fluctuations during the high-altitude cusp crossing on 17 March 2001. Despite the quiet solar wind conditions, the cusp was filled with magnetic field turbulence whose power correlates with the field-aligned ion plasma flux. The magnetic field wave spectra shows power law behavior with both double and single slopes with break in the spectra usually occurring in the vicinity of the local ion cyclotron frequency. Strong peaks in the wave power close to local ion cyclotron frequency were sometimes observed, with secondary peaks at higher harmonics indicative of resonant processes between protons and the waves. We show that the observed spectral break point may be caused partly by damping of obliquely propagating kinetic Alfvén (KAW waves and partly by cyclotron damping of ion cyclotron waves.

  7. UV-B impairs growth and gas exchange in grapevines grown in high altitude.

    Science.gov (United States)

    Berli, Federico J; Alonso, Rodrigo; Bressan-Smith, Ricardo; Bottini, Rubén

    2013-09-01

    We previously demonstrated that solar ultraviolet-B (UV-B) radiation levels in high altitude vineyards improve berry quality in Vitis vinifera cv. Malbec, but also reduce berry size and yield, possibly as a consequence of increased oxidative damage and growth reductions (lower photosynthesis). The defense mechanisms toward UV-B signal and/or evoked damage promote production of antioxidant secondary metabolites instead of primary metabolites. Purportedly, the UV-B effects will depend on tissues developmental stage and interplay with other environmental conditions, especially stressful situations. In this work, grapevines were exposed to high solar UV-B (+UV-B) and reduced (by filtering) UV-B (-UV-B) treatments during three consecutive seasons, and the effects of UV-B, developmental stages and seasons on the physiology were studied, i.e. growth, tissues morphology, photosynthesis, photoprotective pigments, proline content and antioxidant capacity of leaves. The +UV-B reduced photosynthesis and stomatal conductance, mainly through limitation in gas exchange, reducing plant's leaf area, net carbon fixation and growth. The +UV-B augmented leaf thickness, and also the amounts of photoprotective pigments and proline, thereby increasing the antioxidant capacity of leaves. The defense mechanisms triggered by + UV-B reduced lipid peroxidation, but they were insufficient to protect the photosynthetic pigments per leaf dry weight basis. The +UV-B effects depend on tissues developmental stage and interplay with other environmental conditions such as total radiation and air temperatures.

  8. Four point measurements of electrons using PEACE in the high-altitude cusp

    Directory of Open Access Journals (Sweden)

    M. G. G. T. Taylor

    Full Text Available We present examples of electron measurements from the PEACE instruments on the Cluster spacecraft in the high-latitude, high-altitude region of the Earth’s magnetosphere. Using electron density and energy spectra measurements, we examine two cases where the orbit of the Cluster tetrahedron is outbound over the northern hemisphere, in the afternoon sector approaching the magnetopause. Data from the magnetometer is also used to pinpoint the position of the spacecraft with respect to magnetospheric boundaries. This preliminary work specifically highlights the benefit of the multipoint measurement capability of the Cluster mission. In the first case, we observe a small-scale spatial structure within the magnetopause boundary layer. The Cluster spacecraft initially straddle a boundary, characterised by a discontinuous change in the plasma population, with a pair of spacecraft on either side. This is followed by a complete crossing of the boundary by all four spacecraft. In the second case, Cluster encounters an isolated region of higher energy electrons within the cusp. The characteristics of this region are consistent with a trapped boundary layer plasma sheet population on closed magnetospheric field lines. However, a boundary motion study indicates that this region convects past Cluster, a characteristic more consistent with open field lines. An interpretation of this event in terms of the motion of the cusp boundary region is presented.

    Key words. Magnetospheric physics (magnetopause, cusp and boundary layers; solar wind-magnetosphere interactions

  9. ON THE ORIGIN OF HIGH-ALTITUDE OPEN CLUSTERS IN THE MILKY WAY

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Medina, L. A.; Pichardo, B.; Moreno, E.; Peimbert, A. [Instituto de Astronomía, Universidad Nacional Autónoma de México, A.P. 70-264, 04510, México, D.F., México (Mexico); Velazquez, H., E-mail: lamartinez@astro.unam.mx [Instituto de Astronomía, Universidad Nacional Autónoma de México, Apartado Postal 877, 22860 Ensenada, B.C., México (Mexico)

    2016-01-20

    We present a dynamical study of the effect of the bar and spiral arms on the simulated orbits of open clusters in the Galaxy. Specifically, this work is devoted to the puzzling presence of high-altitude open clusters in the Galaxy. For this purpose we employ a very detailed observationally motivated potential model for the Milky Way and a careful set of initial conditions representing the newly born open clusters in the thin disk. We find that the spiral arms are able to raise an important percentage of open clusters (about one-sixth of the total employed in our simulations, depending on the structural parameters of the arms) above the Galactic plane to heights beyond 200 pc, producing a bulge-shaped structure toward the center of the Galaxy. Contrary to what was expected, the spiral arms produce a much greater vertical effect on the clusters than the bar, both in quantity and height; this is due to the sharper concentration of the mass on the spiral arms, when compared to the bar. When a bar and spiral arms are included, spiral arms are still capable of raising an important percentage of the simulated open clusters through chaotic diffusion (as tested from classification analysis of the resultant high-z orbits), but the bar seems to restrain them, diminishing the elevation above the plane by a factor of about two.

  10. Technologies of oxygen supply for life support during the development of mineral resources in high altitude areas

    Institute of Scientific and Technical Information of China (English)

    Liu Yingshu; Jia Yanxiang; Wu Tianyi; Deng Ling; Yang Xiong; Liu Wenhai; Zhang Hui

    2013-01-01

    In order to fulfill the needs of life-support oxygen supply during the development of plateau mineral resources,four oxygen supply patterns suitable for the plateau mine in specific environment were developed:tunnel face diffusive oxygen supply,tunnel oxygen-bar car,carried oxygen cylinder and portable oxygen generator.Through the study of safety oxygen supply experiments in low-pressure plateau areas,the mathematical relationship between maximum integration of secure oxygen volume and altitude has been achieved.Oxygen supply safety control should follow this relationship in plateau mines during the time of executing tunnel face or in room air diffusive oxygen supply.The application results of life-support oxygen supplement technologies in the development of mineral resources in high altitude areas show that the oxygen supply for tunneling miners in plateau mines can not only effectively enhance the oxygen saturation,reduce the pulse rate and the breath rate per minute,but also improve various symptoms caused by altitude hypoxia and high-intensity physical labor.

  11. Maximal exercise and muscle oxygen extraction in acclimatizing lowlanders and high altitude natives

    DEFF Research Database (Denmark)

    Lundby, Carsten; Sander, Mikael; van Hall, Gerrit

    2006-01-01

    values obtained at sea level, the former values were almost completely restored to sea level values. This would suggest that the major determinant V(o2max)for not to increase with acclimatization is the observed reduction in maximal leg blood flow and O(2) conductance.......The tight relation between arterial oxygen content and maximum oxygen uptake (Vv(o2max)within a given person at sea level is diminished with altitude acclimatization. An explanation often suggested for this mismatch is impairment of the muscle O(2) extraction capacity with chronic hypoxia...... O(2) extraction at maximal exercise was 90.0+/-1.0% in the Danish lowlanders at sea level, and remained close to this value in all situations. In contrast to this, fractional arterial O(2) extraction was 83.2+/-2.8% in the high altitude natives, and did not change with the induction of normoxia...

  12. Low altitude high speed cargo parachute system development: A status report

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, W.D.; Alsbrooks, T.H.; Ronquillo, K.L. (Sandia National Labs., Albuquerque, NM (USA)); Sadeck, J.E.; Lee, C.K. (Army Natick Research, Development and Engineering Center, MA (USA))

    1991-01-01

    A Low Altitude High Speed Cargo (LAHSC) parachute is being developed for deployment at velocities up to 250 knots at 300 ft altitude. The LAHSC parachute will decelerate and turnover a load to a 40 to 60 ft/sec vertical velocity at first vertical at approximately 30 ft AGL. The acceleration limit is 5 g's. Main chute cargo extraction will be necessary. A single parachute will be utilized for a 7500 lb load, and clusters will be used for larger loads. The 64-gore, 70-ft-dia parachute has a ring-slot/solid construction with a flare at the skirt to aid the inflation. This paper describes the parachute, the design process and testing to date. Model parachutes have been tested in wind tunnels and in free flight. A single full-scale parachute has been tested at low speeds with conventional load extraction, and with a vertical trajectory at deployment. 5 refs., 18 figs., 3 tabs.

  13. Elevation of circulating miR-210-3p in high-altitude hypoxic environment

    Directory of Open Access Journals (Sweden)

    Yan eYan

    2016-03-01

    Full Text Available Background: The induction of miR-210-3p, a master hypoxamir, is a consistent feature of the hypoxic response in both normal and malignant cells. However, whether miR-210-3p acts as a circulating factor in response to a hypoxic environment remains unknown. The current study aimed to examine the effect of a high-altitude hypoxic environment on circulating miR-210-3p.Methods: We examined and compared the levels of miR-210-3p using TaqMan-based qRT-PCR in both peripheral blood cells and plasma from 84 ethnic Chinese Tibetans residing at 3560 m, 46 newly arrived migrant Han Chinese (Tibet Han and 82 Han Chinese residing at 8.9 m (Nanjing Han. Furthermore, we analyzed the correlations of miR-210-3p with hematological indices. Results: The relative concentrations of miR-210-3p to internal reference U6 in blood cells were significantly higher in the Tibet Han group (1.01±0.11, P<0.001 and in the Tibetan group (1.17±0.09, P<0.001 than in the Nanjing Han group (0.51±0.04. The absolute concentrations of plasma miR-210-3p were also markedly elevated in the Tibet Han group (503.54±42.95 fmol/L, P=0.004 and in the Tibetan group (557.78±39.84 fmol/L, P<0.001 compared to the Nanjing Han group (358.39±16.16 fmol/L. However, in both blood cells and plasma, miR-210-3p levels were not significantly different between the Tibet Han group and the Tibetan group (P=0.280, P=0.620, respectively. Plasma miR-210-3p concentrations were positively correlated with miR-210-3p levels in blood cells (r=0.192, P=0.005. Furthermore, miR-210-3p levels in both blood cells and plasma showed strong positive correlations with red blood cell counts and hemoglobin and hematocrit values. Conclusion: These data demonstrated, for the first time, that miR-210-3p might act as a circulating factor in response to hypoxic environments and could be associated with human adaptation to life at high altitudes.

  14. Urban ectopy in the mountains: Carbon monoxide exposure at high altitude

    Energy Technology Data Exchange (ETDEWEB)

    Leaf, D.A. [Univ. of California Medical Center, Los Angeles, CA (United States); Kleinman, M.T. [Univ. of California, Irvine, CA (United States)

    1996-07-01

    Environmental exposure to inhaled carbon monoxide (CO) increases coronary artery disease risk. Sudden cardiac death, a frequent manifestation of coronary artery disease, is usually a result of ventricular dysrhythmia. The effect of exposure to CO at sea level (CO/SL) and simulated high (2.1 km) altitudes (CO/HA) on the incidence of cardiac ectopy in subjects with coronary artery disease was investigated. A double-blind crossover study was conducted, with random-order assignment, and each subject served as his own control. Seventeen men with documented coronary artery disease and stable angina pectoris performed cardiopulmonary exercise stress tests after random exposure to either CO or clean air (CA) at sea level (CA/SL) or at a simulated 2.1-km high altitude (CA/HA). The individual CO and HA exposure conditions were each selected to reduce the percentage of oxygen saturation of the subjects arterial blood by 4%. Subjects blood carboxyhemoglobin levels were increased form an average of 0.62% after clean-air exposure to 3.91% of saturation after CO exposure. The percentage of oxygen saturation in arterial blood was reduced from a baseline level of 98% to approximately 94% after CO/SL or CA/HA and to approximately 90% after CO/HA. Compared with the CA/SL the average incidence of exercise-induced ventricular ectopy was approximately doubled after all exposures and a significant trend (p {le} .05) of increased ectopy with decreased oxygen saturation in arterial blood was observed. Yet, among subjects who were free from ectopy (n=11) on CA/SL, only 2 subjects developed ectopy after CO/HA. No episodes of ventricular tachycardia or fibrillation occurred. The findings indicated that exposure to increased levels of hypoxemia, resulting from hypoxic and/or CO exposures, increased the susceptibility to ventricular ectopy during exercise in individuals with stable angina pectoris; however, this risk was nominal for those without ectopy. 26 refs., 1 fig., 2 tabs.

  15. Variability of sunspot cycle QBO and total ozone over high altitude western Himalayan regions

    Science.gov (United States)

    Ningombam, Shantikumar Singh

    2011-10-01

    Long-term trend of total column ozone at high altitude region in Ladakh is studied, using a total ozone mapping spectrometer and an ozone monitoring instrument during 1979-2008. In the region, total ozone exhibits seasonality with maximum in spring and minimum in autumn. The decreasing trend of total ozone was found as -2.51±0.45% per decade with 95% confidence level in the region. Ozone deficiency in the Ladakh region is strongest (-33.9 DU at Hanle) in May and weakest (-11.5 DU at Hanle) in January-February. In the study, the solar maximum in 1990 is in phase with ozone maximum, while ozone variation lags in phase with the 1980 and 2000 solar maxima. However, a significant correlation between total ozone and sunspot number is achieved in the westerly phase of quasi-biennial oscillation during spring season. Decreasing trend of ozone in the region is correlating well with the cooling rate in the lower stratosphere.

  16. HAVOC: High Altitude Venus Operational Concept - An Exploration Strategy for Venus

    Science.gov (United States)

    Arney, Dale; Jones, Chris

    2015-01-01

    The atmosphere of Venus is an exciting destination for both further scientific study and future human exploration. A lighter-than-air vehicle can carry either a host of instruments and probes, or a habitat and ascent vehicle for a crew of two astronauts to explore Venus for up to a month. The mission requires less time to complete than a crewed Mars mission, and the environment at 50 km is relatively benign, with similar pressure, density, gravity, and radiation protection to the surface of Earth. A recent internal NASA study of a High Altitude Venus Operational Concept (HAVOC) led to the development of an evolutionary program for the exploration of Venus, with focus on the mission architecture and vehicle concept for a 30 day crewed mission into Venus's atmosphere. Key technical challenges for the mission include performing the aerocapture maneuvers at Venus and Earth, inserting and inflating the airship at Venus, and protecting the solar panels and structure from the sulfuric acid in the atmosphere. With advances in technology and further refinement of the concept, missions to the Venusian atmosphere can expand humanity's future in space.

  17. Vitamin D, Iron Metabolism, and Diet in Alpinists During a 2-Week High-Altitude Climb.

    Science.gov (United States)

    Kasprzak, Zbigniew; Śliwicka, Ewa; Hennig, Karol; Pilaczyńska-Szcześniak, Łucja; Huta-Osiecka, Anna; Nowak, Alicja

    2015-09-01

    A defensive mechanism against hypobaric hypoxia at high altitude is erythropoesis. Some authors point to the contribution of vitamin D to the regulation of this process. The aim of the present study was to assess the 25-hydroxycholecalciferol (25(OH)D) level and its associations with iron metabolic and inflammatory indices in participants of a 2-week mountaineering expedition. The study sample included 9 alpinists practicing recreational mountain climbing. Every 2 or 3 days they set up a different base between 3200 and 3616 m with the intention of climbing 4000