Transitional fossilA transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group. This is especially important where the descendant group is sharply differentiated by gross anatomy and mode of living from the ancestral group. These fossils serve as a reminder that taxonomic divisions are human constructs that have been imposed in hindsight on a continuum of variation.
Geopotential heightGeopotential height or geopotential altitude is a vertical coordinate referenced to Earth's mean sea level (assumed zero potential) that represents the work done by lifting one unit mass one unit distance through a region in which the acceleration of gravity is uniformly 9.80665 m/s2. Geopotential height (altitude) differs from geometric (tapeline) height but remains a historical convention in aeronautics as the altitude used for calibration of aircraft barometric altimeters.
High-altitude pulmonary edemaHigh-altitude pulmonary edema (HAPE) is a life-threatening form of non-cardiogenic pulmonary edema that occurs in otherwise healthy people at altitudes typically above . However, cases have also been reported between in more vulnerable subjects. Classically, HAPE occurs in persons normally living at low altitude who travel to an altitude above 2,500 meters (8,200 feet). Re-entry HAPE is also an entity that has been described in persons who normally live at high altitude but who develop pulmonary edema after returning from a stay at low altitude.
Age and female fertilityFemale fertility is affected by age and is a major fertility factor for women. A woman's fertility is in generally good quality from the late teens to early thirties, although it declines gradually over time. Around 35, fertility is noted to decline at a more rapid rate. While many sources suggest a more dramatic drop at around 35, this is unclear, since few studies have been conducted since the 19th century. One 2004 study of European women found fertility of the 27–34 and the 35–39 groups had only a four-percent difference.
Female infertilityFemale infertility refers to infertility in women. It affects an estimated 48 million women, with the highest prevalence of infertility affecting women in South Asia, Sub-Saharan Africa, North Africa/Middle East, and Central/Eastern Europe and Central Asia. Infertility is caused by many sources, including nutrition, diseases, and other malformations of the uterus. Infertility affects women from around the world, and the cultural and social stigma surrounding it varies.
