Age is no barrier to success at very high altitudes

Abstract The lichen Lecanora somervellii Paulson, first described from the northern slopes of Mt Everest in Tibet, has been collected at four other localities in the High Himalayas, at altitudes between 3750 and 5540 m. As the type material appears to be missing, a neotype is designated here. The species has an unusual lemon yellow colour due to the pigment calycin; this compound is in addition to usnic acid, which is widespread in Lecanora. Lecanora somervellii is otherwise very similar in essential characters to the complex including Lecanora concolor Ram. and L. orbicularis (Schaerer) Vainio, high alpine species well-known, for example, from the Alps. It is supposed, that L. somervellii is derived from this aggregate by the production of calycin (in addition to usnic acid), which acts as an additional protective pigment at these very high altitudes.

Download Full-text

Comparison Between Pressure Swing Adsorption and Liquid Oxygen Enrichment Techniques in the Atacama Large Millimeter/Submillimeter Array Facility at the Chajnantor Plateau (5,050 m)

Frontiers in Physiology ◽

10.3389/fphys.2021.775240 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ivan Lopez ◽

Reinaldo Aravena ◽

Daniel Soza ◽

Alicia Morales ◽

Silvia Riquelme ◽

...

Keyword(s):

High Altitude ◽

Pressure Swing Adsorption ◽

Large Scale ◽

High Mobility ◽

Oxygen Enrichment ◽

Oxygen Availability ◽

Liquid Oxygen ◽

High Altitudes ◽

Pressure Swing ◽

Very High

The Chilean workforce has over 200,000 people that are intermittently exposed to altitudes over 4,000 m. In 2012, the Ministry of Health provided a technical guide for high-altitude workers that included a series of actions to mitigate the effects of hypoxia. Previous studies have shown the positive effect of oxygen enrichment at high altitudes. The Atacama Large Millimeter/submillimeter Array (ALMA) radiotelescope operates at 5,050 m [Array Operations Site (AOS)] and is the only place in the world where pressure swing adsorption (PSA) and liquid oxygen technologies have been installed at a large scale. These technologies reduce the equivalent altitude by increasing oxygen availability. This study aims to perform a retrospective comparison between the use of both technologies during operation in ALMA at 5,050 m. In each condition, variables such as oxygen (O2), temperature, and humidity were continuously recorded in each AOS rooms, and cardiorespiratory variables were registered. In addition, we compared portable O2 by using continuous or demand flow during outdoor activities at very high altitudes. The outcomes showed no differences between production procedures (PSA or liquid oxygen) in regulating oxygen availability at AOS facilities. As a result, big-scale installations have difficulties reaching the appropriate O2 concentration due to leaks in high mobility areas. In addition, the PSA plant requires adequacy and maintenance to operate at a very high altitude. A continuous flow of 2–3 l/min of portable O2 is recommended at 5,050 m.

Download Full-text

Aerodynamics of typical lifting bodies under conditions simulating very high altitudes.

AIAA Journal ◽

10.2514/3.3946 ◽

1967 ◽

Vol 5 (2) ◽

pp. 226-232 ◽

Cited By ~ 12

Author(s):

D. E. BOYLAN ◽

J. L. POTTER

Keyword(s):

High Altitudes ◽

Very High

Download Full-text

Physiological Changes at Altitude in Nonasthmatic and Asthmatic Subjects

Canadian Respiratory Journal ◽

10.1155/2004/734760 ◽

2004 ◽

Vol 11 (3) ◽

pp. 197-199 ◽

Cited By ~ 13

Author(s):

Dianna Louie ◽

Peter D Paré

Keyword(s):

Peak Expiratory Flow ◽

Arterial Oxygen Saturation ◽

Arterial Oxygen ◽

Physiological Changes ◽

High Altitudes ◽

Exercise Challenge ◽

Per Se ◽

Expiratory Flow ◽

Exercise Induced ◽

Very High

Exercised-induced asthma is not due to exercise itself per se, but rather is due to cooling and/or drying of the airway because of the increased ventilation that accompanies exercise. Travel to high altitudes is accompanied by increased ventilation of cool, often dry, air, irrespective of the level of exertion, and by itself, this could represent an 'exercise' challenge for asthmatic subjects. Exercise-induced bronchoconstriction was measured at sea level and at various altitudes during a two-week trek through the Himalayas in a group of nonasthmatic and asthmatic subjects. The results of this study showed that in mild asthmatics, there was a significant reduction in peak expiratory flow at very high altitudes. Contrary to the authors' hypothesis, there was not a significant additional decrease in peak expiratory flow after exercise in the asthmatic subjects at high altitude. However, there was a significant fall in arterial oxygen saturation postexercise in the asthmatic subjects, a change that was not seen in the nonasthmatic subjects. These data suggest that asthmatic subjects develop bronchoconstriction when they go to very high altitudes, possibly via the same mechanism that causes exercise-induced asthma.

Download Full-text

Physiological and LLCS Measurements of 11 Nepali Guides and 2 Westerners in Fast Ascents to Very High Altitudes: A Controlled Study

Wilderness and Environmental Medicine ◽

10.1016/j.wem.2012.07.008 ◽

2013 ◽

Vol 24 (1) ◽

pp. 80-81

Author(s):

Anne M. Anglim ◽

Daniel W. Boyd

Keyword(s):

Controlled Study ◽

High Altitudes ◽

Very High

Download Full-text

Laying Eggs at High Altitude

Physiology ◽

10.1152/physiologyonline.1988.3.2.69 ◽

1988 ◽

Vol 3 (2) ◽

pp. 69-71 ◽

Cited By ~ 1

Author(s):

CC Monge ◽

F Leon-Velarde ◽

G Gomez de la Torre

Keyword(s):

High Altitude ◽

Water Loss ◽

Oxygen Supply ◽

The Other ◽

High Altitudes ◽

High Mountains ◽

The One ◽

Very High

The hypoxic and dry environment of the high mountains seems to select eggshells with porosities appropriate for the altitudinal level. At moderate altitudes, the conservation of water takes precedence over the oxygen-supply gradient. At very high altitudes there is a compromise between reducing water loss on the one hand and the defense of the oxygen supply to the embryo on the other.

Download Full-text