Solar energy can be used and so can hydroelectricity
Let us consider the centripetal force equation,
centripetal force F = mv² / r
f= force
v= velocity
m= mass
r= radius.
in all the factors only velocity has the power of 2. so when you double the velocity then it will become square of that.
if v= 2v , F = m4v² / r
so velocity is doubled it would produce the greatest change in the centripetal force.
Bacteria in our gut help to protect us by crowding out some of their dangerous relatives that can cause disease. Other good bacteria have been used in medicine to create antibiotics, and others still are used in food production to make fermented foods (think sauerkraut, yogurt, kimchi and kombucha.)
Answer:
The fewer number of T cells a person has, the more chances to be affected by an opportunistic infection. When the number of T cells reaches 200 cells/µl, the person is at risk of being infected by other infections.
Explanation:
The whole immune system of a person who is infected with HIV infection seems to be severely affected. When the person is not treated or the disease is in a very advanced stage, the depletion of the T- cells turns to be very sharped, especially CD4+ T cells. At this point, the immune system can not resist the attack of other microorganisms. The <em>lower is the number of CD4+ T Cells, the higher possibility the person has to be attacked by opportunistic infections. </em>
Classically, it has been suggested that opportunistic infections appear after the CD4 + T lymphocytes reach very low levels, such as 200 cells/µl. The number of circulating T cells can be used as an indicator and a measure of global "immune competence", and the previously mentioned amount of CD4 + T cells is an accepted universal reference used to predict the risk of having one of these opportunistic infections.