Eutrophication of lakes. Some lakes also demonstrate the reverse process (meiotrophication), becoming less nutrient rich with time. The main difference between natural and anthropogenic eutrophication is that the natural process is very slow, occurring on geological time scales. Eutrophication is a common phenomenon in coastal waters. In contrast to freshwater systems, nitrogen is more commonly the key limiting nutrient of marine waters; thus, nitrogen levels have greater importance to understanding eutrophication problems in salt water. Estuaries tend to be naturally eutrophic because land-derived nutrients are concentrated where run-off enters a confined channel. Upwelling in coastal systems also promotes increased productivity by
Artificial cartilage field. Artificial cartilage is a new research topic and much is still unknown. There is a lot of unknown factors involving ASCPs and more studies need to be conducted to make a more supported conclusion about the regenerative functions of ASCPs. Additionally, growth factors have been thoroughly evaluated, however specific combinations still need to be studied further in order to more effectively generate a tissue that can mimic the properties of natural cartilage. Artificial cartilage Artificial cartilage is a synthetic material made of hydrogels or polymers that aims to mimic the functional properties of natural cartilage in the human body.