(more on Power Words)
average (in science) An expression of the arithmetic mean which is the sum of a group of numbers which is then divided by the size of the group.
infectious An adjective for a disease that can be spread by direct contact with an infected individual or the bacteria that they throw into the air, their clothing or their environment. Such diseases are called infectious.
Ebola A family of viruses that cause a fatal disease in humans. All cases have arisen in Africa. Its symptoms include headache, fever, muscle pain and extensive bleeding. The infection spreads from person to person (or animal to a person) upon contact with infected body fluids. The disease gets its name from where the infection was first discovered in 1
New Infectious Disease A disease that has suddenly begun to infect increasing numbers of people or other organisms and could increase dramatically, more in the near future.
environment The sum of all the things that exist around an organism or process and the condition these things create. Environment can refer to weather and ecosystem where some animals live, or maybe temperature and humidity (or even location of objects near an object).
epidemic A widespread outbreak of a contagious disease that afflicts many people (or other organisms) in a society at the same time. The term can also be applied to non-infectious diseases or conditions that have spread in a similar manner.
epidemiologist As researchers in the field of health, scientists discover what causes a particular disease and how to limit its spread.  factor Something that plays a role in a particular state or event; a contributor.
herd immunity An expression that refers to the idea that if most people in a population are immune to a disease, then they cannot spread it. This tends to protect most people who are not immune.
(adj.) Having to deal with immunity. (v.) able to avert a particular infection. Alternatively, this term can be used to mean that an organism does not exhibit any influence from exposure to a particular poison or process. More generally, the term may indicate that something cannot be damaged by a particular substance, disease or chemical.
immune system The collection of cells and their reactions that help the body fight infections and treat foreign substances that can cause allergies.
Immunity The ability of an organism to withstand a particular infection or venom by allowing the cells to remove, kill or disarm the hazardous substance or infectious germ. Or, when used in unison, it means the ability to avoid another form of negative impact (such as firing from a job or bullying).
infect (adj. infectious ) To spread a disease from one organism to another. This usually involves introducing some sort of pathogenic germ to an individual. Measles A highly contagious disease that typically affects children. Symptoms include a characteristic rash across the body, headache, runny nose and cough. Some people also develop pinkeye, a swelling of the brain (which can cause brain damage) and pneumonia. Both of the latter two complications can lead to death. Fortunately, since the mid-1960s there has been a vaccine to dramatically reduce the risk of infection.
Outbreak The sudden onset of disease in a population of humans or animals. The term can also be used for the sudden emergence of devastating natural phenomena, such as earthquakes or tornadoes.
population (in biology) A group of individuals of the same species living in the same area.
interval The full extent or distribution of something. For example, a plant or animal range is the area where it naturally occurs. (in mathematics or for measurements) Whether variation in values is possible. Also the distance within which something can be reached or perceived.
relationship Relationship between two numbers or amounts. When printing, the numbers are usually separated by a colon, such as a colon. And 50:50. That would mean that for every 50 units of one thing (left) there would also be 50 units of another thing (represented by the number to the right).
strain (in biology) Organisms belonging to the same species that share some small but definable properties. For example, biologists breed certain strains of mice that may have a particular susceptibility to disease. Certain bacteria or viruses may develop one or more mutations that make them a strain immune to the usual lethal effect of one or more drugs.
threshold A lower limit; or the lowest level where something arises.
transmission Something that is transported or shipped together. (in mechanics) In a vehicle with liquid fuel, the machine is used to transfer power from the engine to the drive wheels. (In medicine) To spread a disease or a toxic substance.
vaccine (v. Vaccinat) A biological mixture resembling a pathogen. It is given to help the body create immunity to a particular disease. The injections used for the administration of most vaccines are known as vaccinations.
variable (in mathematics) A letter used in a mathematical expression that can assume different values. (in trial) A factor that can be changed, especially one allowed to change in a scientific experiment. For example, when scientists measure how much insecticide it can take to kill a fly, they can change the dose or age at which the insect is exposed. Both dose and age would be variables in this experiment.
Small infectious particles consisting of RNA or DNA surrounded by protein. Viruses can reproduce only by injecting their genetic material into the cells of living creatures. Although scientists often refer to viruses as living or dead, there are actually no viruses alive. It doesn't eat like animals do, or does its own food as the plants do. It must hijack the cellular machinery of a living cell to survive.