Flu-like Illness. One of the earliest HIV symptoms in men is a severe 'flu-like' illness, known as the 'seroconversion illness.'. Seroconversion is the point in time where a person's blood is converted from being HIV negative to HIV positive, by the production of antibodies.
Erosion causes the surface of mountains to be younger than the rocks that form the mountains themselves. Glacial processes produce characteristic landforms, such as pyramidal peaks, knife-edge arÃªtes, and bowl-shaped cirques that can contain lakes.
Deserts may be formed by any of the following: 1  Deforestation - when trees are cut down, there are no tree roots to hold the soil in place. 2  Deserts may be caused by rain shadows, when mountain ranges prevent clouds from reaching inland.  High altitude may result in deserts.