Avascular necrosis (AVN) of the hip is an abnormal and possibly crippling condition in which blood cannot get to the hip bone. When the blood supply to the bone is blocked, the area without blood supply can die. This may lead to collapse of the bone requiring replacement with an artificial hip joint.
Nitrogen Fixing Trees for Permaculture Flowers of the leguminous tree, Kowhai, the national flower of New Zealand Nitrogen fixation is a pattern of nutrient cycling which has successfully been used in perennial agriculture for millennia. This article focuses on legumes, which are nitrogen fixers [â¦]
Therefore, nitrogen fixation is essential for agriculture and the manufacture of fertilizer. It is also an important process in the manufacture of explosives (e.g. gunpowder, dynamite, TNT, etc.). Nitrogen fixation occurs naturally in the air by means of lightning.Biological nitrogen fixation can include conversion to nitrogen dioxide. All biological nitrogen fixation is done by way of nitrogenase metalo-enzymes which contain iron, molybdenum, or vanadium.Microorganisms that can fix nitrogen are prokaryotes (both bacteria and archaea, distributed throughout their respective kingdoms) called diazotrophs.iological nitrogen fixation was discovered by the German agronomist Hermann Hellriegel and Dutch microbiologist Martinus Beijerinck. Biological nitrogen fixation (BNF) occurs when atmospheric nitrogen is converted to ammonia by an enzyme called a nitrogenase.