Importance and Value of Trees. Since the beginning, trees have furnished us with two of lifeâs essentials, food and oxygen. As we evolved, they provided additional necessities such as shelter, medicine, and tools. Today, their value continues to increase and more benefits of trees are being discovered as their role expands to satisfy the needs created by our modern lifestyles.
However, the most serious is called psittacosis. With this disease, an agent called Chlamydia psittaci causes it, and the disease is also called ornithosis. Birds can be asymptomatic carriers, and may only fall ill when upset, as stress is a major component in all avian diseases.
Mad cow disease, or bovine spongiform encephalopathy (BSE), is a transmissible, slowly progressive, degenerative, and fatal disease affecting the central nervous system of adult cattle. The U.S. Department of Agriculture (USDA) has tested hundreds of thousands of cattle for BSE.Researchers believe that the infectious agent that causes mad cow disease is an abnormal version of a protein normally found on cell surfaces, called a prion.For reasons still unknown, this protein becomes altered and destroys nervous system tissue -- the brain and spinal cord.he U.S. Department of Agriculture (USDA) has tested hundreds of thousands of cattle for BSE. Researchers believe that the infectious agent that causes mad cow disease is an abnormal version of a protein normally found on cell surfaces, called a prion.