Related Experiment Video
Updated: Jun 11, 2026
07:26
Synthesis and Microdiffraction at Extreme Pressures and Temperatures
Published on: October 7, 2013
Caudwell xtreme Everest expedition.
Michael P W Grocott1, Daniel S Martin, Mark H Wilson
1mike.grocott@ucl.ac.uk <mike.grocott@ucl.ac.uk>
High Altitude Medicine & Biology
|July 1, 2010
Summary
The Caudwell Xtreme Everest expedition studied human adaptation to extreme altitude. Researchers collected unique physiological data, including blood gases and microcirculation, at altitudes above 5500m.
Area of Science:
- Physiology
- Altitude Medicine
- Extreme Environment Research
Background:
- The Caudwell Xtreme Everest (CXE) expedition studied 222 subjects ascending above 5300m in 2007.
- Focus on investigator-subjects (n=24) at extreme altitude (>5500m) for physiological data collection.
- Included trekkers to Everest Base Camp (EBC) and a subgroup (n=14) collecting data higher on Everest.
Purpose of the Study:
- To investigate physiological responses to extreme altitude exposure.
- To collect unique data on oxygen consumption, cerebral blood flow, and microcirculation.
- To analyze arterial blood gas values at very high altitudes.
Main Methods:
- Measurements of peak oxygen consumption, middle cerebral artery diameter and velocity, and microcirculatory blood flow at the South Col (7950m).
- Collection of arterial blood gas samples from 4 subjects at 8400m during descent from the summit.
- Analysis of published data from investigator-subjects at extreme altitude.
Main Results:
- Unique physiological measurements were obtained at extreme altitudes.
- Arterial blood gas values and microcirculatory blood flow data were detailed.
- Data provides insights into human physiological limits at high altitude.
Conclusions:
- The study provides valuable physiological data from extreme altitudes.
- Understanding these responses is crucial for mountaineering and high-altitude medicine.
- Further research can build upon these unique datasets.
Related Concept Videos
01:25Rab Cascades
Rab GTPases act in a regulated cascade during membrane fusion, helping the lipid bilayers mix. The Rab family of proteins are active when bound to GTP, and inactive when bound to GDP. Hence, they act as guanine nucleotide-dependent molecular switches. Rab-GTP recognizes and binds to long or short-range tethering proteins to capture the target vesicle. These tethers coordinate with SNAREs on the vesicle and the target membrane to assemble the trans SNARE complex that locks the mixing bilayers.
01:20Elevation of Intermediate Points on Vertical Curves
Vertical curves are essential in roadway design because they provide smooth transitions between varying roadway grades. Designing vertical curves involves calculating intermediate elevations and identifying the curve's highest or lowest point, which is essential for optimal roadway performance.Intermediate elevations on a vertical curve are determined using the tangent offset method. This method considers the initial elevation at the start of the curve, the grades, and the curve's geometry. The...
01:16Eccentric Loading
Eccentric loading is a crucial concept in the study of structural engineering and mechanics, particularly when analyzing the stability and stress distribution in columns. Unlike centric loading, where the force is applied along the centroidal axis, causing uniform compression, eccentric loading occurs when a force is applied off-center. This off-center application introduces not only direct compressive stress but also bending stress, significantly influencing the column's behavior under load.
01:25Eddy Currents
Since eddy currents occur only in conductors, magnets can separate metals from other materials. For example, in a recycling center, trash is dumped in batches down a ramp, beneath which lies a powerful magnet. Conductors in the trash are slowed by eddy currents, while nonmetals in the trash move on, separating from the metals. This works for all metals, not just ferromagnetic ones.
Other major applications of eddy currents appear in metal detectors and the braking systems of trains and roller...
Other major applications of eddy currents appear in metal detectors and the braking systems of trains and roller...
01:21Rolling Resistance
When a solid cylinder rolls steadily on a rigid surface, the normal force applied by the surface on the cylinder is perpendicular to the tangent at the contact point. However, since no materials are entirely rigid, the surface's reaction to the cylinder involves a range of normal pressures.
For instance, imagine a hard cylinder rolling on a comparatively soft surface. The cylinder's weight compresses the surface beneath it. As the cylinder moves, the material in front of it slows down due to...
For instance, imagine a hard cylinder rolling on a comparatively soft surface. The cylinder's weight compresses the surface beneath it. As the cylinder moves, the material in front of it slows down due to...
01:29Topographic Surveying and Contours
Topographic surveying is critical for documenting the Earth's surface, focusing on capturing elevations, slopes, and natural and man-made features. It is essential in construction planning, water resource management, and land-use analysis. The primary outcome of such surveys is a topographic map, which uses contour lines to visually represent the shape and slope of the terrain, providing valuable insights into the landscape's characteristics.Contour lines are fundamental to understanding the...