Knowledge about the phylogeny and ecology of communities along environmental gradients helps to disentangle the role of competition-driven processes and environmental filtering for community assembly. In this study, we evaluated patterns in species richness, phylogenetic structure and life-history traits of bee communities along altitudinal gradients in the Alps, Germany. We found a linear decl...

The distributions of American cicada killers (Sphecius) were examined via solicited and museum specimens. S. hogardii occurs in southern Florida and several Caribbean islands. S. speciosus occurs throughout the east coast, southeast, and Midwestern states at high densities, and its range extends much farther west than expected, but not west of the continental divide. S. speciosus appears to be ...

OBJECTIVE Discuss the effects of altitude exposure on neuropsychological functions. METHOD We have conducted a literature review using as source indexed articles at Pubmed in the period from 1921 to 2008, using the following key words: 'cognition and hypoxia', 'hypoxia and neuropsychology', 'acute hypoxia', 'chronic hypoxia', and 'acclimatization and hypoxia', as well as specific books on the...

Tibetan yak (Bos grunniens) inhabiting the Qinghai-Tibet Plateau (QTP) where the average altitude is 4000 m, is specially adapted to live at these altitudes. Conversely, cattle (B. taurus) has been found to suffer from high-altitude hypertension or heart failure when exposed to these high altitudes. Two mitochondrial genes, MT-ND1 and MT-ND2, encode two subunits of NADH dehydrogenase play an es...

Background Cardiac structural and functional changes due to chronic exposure to moderately high altitudes (HA) have been poorly described. There are many larger cities with altitudes above 2000 meters over sea level (OSL) where this information is relevant. The purpose of our investigation was to identify whether chronic hemodynamic changes and tissue abnormalities were present in those native ...

It is a strange coincidence that the highest point on Earth is very close to the limit of human tolerance to hypoxia. The physiological changes that allow humans to reach these extreme altitudes involve enormous alterations of their normal state. It is useful to contrast this response with two others to high altitude. One is acclimatization that allows lowlanders to ascend to altitudes of up to...

Postural control and joint position sense are essential for safely undertaking leisure and professional activities, particularly at high altitude. We tested whether exposure to a 12-day trek with a gradual ascent to high altitude impairs postural control and joint position sense. This was a repeated measures observational study of 12 military service personnel (28±4 years). Postural control (sw...