نتایج جستجو برای: extreme altitude
تعداد نتایج: 108126 فیلتر نتایج به سال:
BACKGROUND Findings of cerebral cortical atrophy, white matter lesions and microhemorrhages have been reported in high-altitude climbers. The aim of this study was to evaluate structural cerebral changes in a large cohort of climbers after an ascent to extreme altitudes and to correlate these findings with the severity of hypoxia and neurological signs during the climb. METHODS Magnetic reson...
BACKGROUND Cushion plants are commonly considered as keystone nurse species that ameliorate the harsh conditions they inhabit in alpine ecosystems, thus facilitating other species and increasing alpine plant biodiversity. A literature search resulted in 25 key studies showing overwhelming facilitative effects of different cushion plants and hypothesizing greater facilitation with increased envi...
[1] Changes in dissolved organic carbon (DOC) concentration are clearly seen for streams in which chemistry is measured on a high‐frequency/episode basis, but these high‐ frequency data are not available in long‐term monitoring programs. Here we develop statistical models to predict DOC concentrations during spring flood from easily available geographic information system data and base flow che...
Local adaptation frequently occurs across populations as a result of migration-selection balance between divergent selective pressures and gene flow associated with life in heterogeneous landscapes. Studying the effects of selection and gene flow on the adaptation process can be achieved in systems that have recently colonized extreme environments. This study utilizes an endemic South American ...
When people are exposed to the extreme environmental conditions, such as high altitude where there is decrease in temperature and partial pressure of oxygen induces fatigue, insomnia, loss of appetite and increased cardiac output. Hence there is need to improve the appetite through the diet and digestion clout of the individual. In the present review paper the efficiency of digestion is comprom...
Modern humans have occupied almost all possible environments globally since exiting Africa about 100,000 years ago. Both behavioral and biological adaptations have contributed to their success in surviving the rigors of climatic extremes, including cold, strong ultraviolet radiation, and high altitude. Among these environmental stresses, high-altitude hypoxia is the only condition in which trad...
More than 140 million people dwell at altitudes of over 2500 m. The Andes region is home to the greatest population density at an altitude of more than 3500 m. Equally, the number of persons living at sea level (SL) is growing, and they travel to medium, high, or extreme altitudes for occupational or scientific reasons, or to enjoy tourism or recreational activities, as is the case of hikers, m...
Genome-wide studies on high-altitude adaptation have received increased attention as a classical case of organismal evolution under extreme environment. However, the current genetic understanding of high-altitude adaptation emanated mainly from autosomal analyses. Only a few earlier genomic studies paid attention to the allosome. In this study, we performed an intensive scan of the X chromosome...
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