Slow blood flow can occur if there is a narrowing of the blood vessel. This can obstruct the flow. One common cause is atherosclerosis. There are deposition of cholesterol or lipids in the wall of the arteries which can narrow it. Other causes can be an inflammation. In the veins there can be slow flow where there is difficulty in pumping blood from legs towards the heart. If you feel any symptom, you should get an examination you need to get it checked by doctor. Any query, please feel free to ask.
Retroviruses belong to the Retroviridae family of viruses. Their genetic material consists of ribonucleic acid (RNA), instead of deoxyribonucleic acid (DNA). Viruses of this type also contain reverse transcriptase. Retroviruses are known to lead to certain types of cancers in both humans and animals, as well as a range of viral infections. Human Immunodeficiency Virus (HIV), the virus that causes Acquired Immune Deficiency Syndrome (AIDS), is one example.
The ICTV classifies RNA viruses as those that belong to Group III, Group IV or Group V of the Baltimore classification system of classifying viruses and does not consider viruses with DNA intermediates in their life cycle as RNA viruses.iruses with RNA as their genetic material but that include DNA intermediates in their replication cycle are called retroviruses, and comprise Group VI of the Baltimore classification. Notable human retroviruses include HIV-1 and HIV-2, the cause of the disease AIDS.