the number of years required for a population to double in size given the present growth rate
The time it would take a population to double, given no changes in age-specific mortality or fertility rates. Any change in the fertility or the mortality graphs changes doubling time. Demography represents doubling times as negative if the population is decreasing. Negative values correspond to ìhalving timeî.
The length of time needed for a population to double in size. It is a function of the growth rate.
The time it will take a population to double in size, assuming the continuation of current rate of growth.
an important indicator of how well a patient will recover from prostate cancer," said Andrew K
a "reasonable surrogate endpoint for survival
a surrogate for time to death
the time it takes a specific focus of the disease to double in size.
In biology, the amount of time it takes for a cell to divide, or for a population of cells (such as a tumor) to double in size. As cells divide more rapidly, the doubling time becomes shorter.
Time it takes the cell population to double in number.
This is the time it takes some entity undergoing growth to double in size. If the growth is exponential, the doubling time is subject to the Law of 70.
The number of years it takes for the population of a given area to double its present size, assuming the current population growth rate holds constant.
The number of years required for the population of an area to double its present size given the current rate of population growth. The life expectancy at birth (this is the number of years a child is expected to live as calculated at the time of birth).
The time that it takes a particular focus of cancer to double in size
The time taken for a population to increase in number by a factor of two.
The number of years it would take for a population to double its current size under a specified constant rate of growth. The time can be calculated by dividing the number 69.3 by the annual percentage growth rate. For example, a constant annual 2% rate of growth would see a population double in 34.65 years.
The time it takes for a tumor or cancerous focus to double in size.
Time it takes (usually in years) for the quantity of something growing exponentially to double. It can be calculated by dividing the annual percentage growth rate into 70. See rule of 70.
The time taken for the PSA (Prostate Specific Antigen) to double, for example from 4 to 8 ng/mL. This is a measure of how fast a cancer is growing and can also be used to predict cancer recurrence after treatment.
In biology, the amount of time it takes for one cell to divide or for a group of cells (such as a tumor) to double in size. The doubling time is different for different kinds of cancer cells or tumors.
The number of years required for the population of an area to double its present size, given the current rate of population growth. Population doubling time is useful to demonstrate the long-term effect of a growth rate, but should not be used to project population size. Many more developed countries have very low growth rates and, as a result, the equation shows doubling times of hundreds or thousands of years. But these countries are not expected to ever double again. Most, in fact, likely have population declines in their future. Many less developed countries have high growth rates that are associated with short doubling times, but are expected to grow more slowly as birth rates are expected to continue to decline. [Note that the U.S. is projected to double. Also see explanation and examples].
the time it takes for a cell to divide and double itself. Cancers vary in doubling time from 8 to 600 days, averaging 100 to 120 days. Thus, a cancer may be present for many years before it can be felt.
The doubling time (also called the generation time) is the period of time required for a quantity to double in size or value. It is applied to population growth, inflation, compound interest, the volume of malignant tumours, and many other things. When the relative growth rate (not the absolute growth rate) is constant, the quantity undergoes exponential growth (also known as geometric growth) and has a fixed doubling time which can be calculated directly from the growth rate.