I read with special interest the Perspective article by Drs Beutler and Waalen1 about the definition of anemia. The authors refer to some variables, such as the sex, age, and race of the individuals, that may influence their levels of hemoglobin in normal conditions. In the final part of their paper, they suggest lower normal levels of hemoglobin for adults, according to their age, sex, and rac...

BACKGROUND Carotid body tumors (CBTs) are rare. Diagnosis is usually delayed until the tumors reach a critical volume and a mass appears in the neck, which is often asymptomatic. METHODS We reviewed retrospectively the cases with CBT diagnosed from 1965 to 1995 in the Hospital de Oncologia in Mexico City with inhabitants at an altitude higher than 2200 m above sea level to see whether these t...

The thesis of this article is quite different from many other theses of papers, books, and articles on the Aral Sea. It is meant to purposely highlight the reality of the situation in Central Asia: the Aral Sea that was once a thriving body of water is no more. That sea is dead. What does exist in its place are the Aral seas: there are in essence three bodies of water, one of which is being pur...

PURPOSE To describe the SpO2 in wakefulness, sleep and during the apnea-hypopnea in adults living in Bogotá, located at 2640 m above sea level. METHODS Descriptive observational study in adults referred for polysomnogram (PSG). A normal Apnea hypopnea index (AHI) was defined as ≤5 and obstructive sleep apnea (OSA) was classified as mild (AHI 5-15), moderate (AHI 15-30), and severe (AHI >30). ...

Improved global mean sea level is obtained by combining two datasets: large-scale mean sea level based on measurements of twin-satellite mission GRACE and mesoscale sea level tilt derived from the momentum balance as seen in drifter, satellite altimeter and wind data. Hybrid product reveals complex structures of main currents even after averaging over 10 years and shows their places in the larg...

BACKGROUND Arterial hemoglobin oxygen saturation (SaO₂) decreases at an altitude of >1,500 m. There are no reports on normal SaO₂ at altitudes between 0 and 1,500 m. The clinical significance of decreased SaO₂ at such altitudes is unclear. OBJECTIVE To test the hypothesis that in healthy volunteers normal SaO₂ at moderate altitude (MA; 725 m) is lower than that at almost sea level (SL; 43 m)....

1. Ecogeomorphic feedbacks between mineral sediment deposition and above-ground plant growth are thought to have dominated the evolution of many coastal ecosystems and landforms. However, land-use-related reductions in sediment delivery rates to estuaries world-wide suggest that these above-ground feedbacks may not apply in some of the world’s most vulnerable coastal landscapes. 2. To understan...

E-PERM(R) radon monitors are based on the principle of electret ion chambers and these are usually calibrated in a standard radon chamber located at sea level. Corrections are needed if these are used in elevations other than sea level. These were experimentally determined for three models of commercially available electret ion chambers (E-PERMS(R)) as functions of elevation above sea level. . ...

Three species of the ophidiid genus Neobythites containing ocelli in the dorsal fin are known from the West Atlantic: Neobythites gilli Goode and Bean 1885, N. ocellatus Günther 1887 and N. monocellatus Nielsen 1999. In the year 2000, 18 specimens of Neobythites were caught on the upper continental slope off eastern Brazil. This is the first documented record of a Neobythites specimen off Brazi...