جستجوی مقالات مرتبط با کلیدواژه « رشد نمایی » در نشریات گروه « پزشکی »

 It is unlikely that the population growth rate has stayed steady in recent years, given the present situation in Iran. There has been a slight rise in population growth over the past 60 years, according to birth, mortality, and census results from 1956 to 2016.

Mathematical modeling is a common element of computer programs used to predict population growth. This model was applied as a useful and instructive tool in the present research to predict Iran's population until 2041.

The standard mathematical modeling approach predicted the total population using the data from Iran's 1956–2016 census using different mathematical modeling methods. The descriptive population growth prediction model (exponential) outperformed the other techniques in terms of compatibility with historical population data. Furthermore, it proved to be highly effective and appropriate for projecting Iran's population in the future. For the year 2041, the following population estimates were projected: A total population of 113,215,189, a male population of 57,366,315, a female population of 55,848,874, an urban population of 83,786,814, a rural population of 29,428,375, and a total population of Iran exceeding 100 million people during the year 2031.

Combining the exponential and hyperbolic extrapolation models allows for the prediction that Iran's population will increase to 159,852,540 people by the year 2075, which is twice as many as that of the 2016 census. Moreover, it is also feasible to calculate the approximate total population that lived 100,000 years before the 1956 census using mathematical modeling.

Electromagnetic fields have various effects on the biochemical and cellular behavior of microorganisms due to radiation. It is necessary to investigate more extensively the effects of these magnetic fields on some microorganisms, such as bacteria. The purpose of this study was tp investigate the effects of magnetic fields on Escherichia coli bacteria (PTCC 1330). E.coli bacteria were prepared in liquid growth medium at the proper density. Then, the bacteria were placed in a magnetic field of 0, 1, 5, 10, 20, 30, 40 and 50 Hz at 0, 4, 8, 12, 16, 20, 24, 28 and 32 time intervals. Afterwards, their population was calculated, and the impact of these waves on the bacteria growth phases, based on the factorial pattern, was measured. Field intensities of 1, 5, 10 and 20 Hz caused an increase in the number of bacteria cells. With increasing field intensity to 50 Hz, the growth of bacteria was reduced. Field intensities of 5, 30, 40 and 50 Hz caused an increment in the time of the lag phase, and field intensities of 1, 10 and 20 Hz caused an increment in the time of the stationary phase. At 1 to 30 Hz field intensities, the duration time of each cell division was reduced, and at 10 Hz field intensity, this reduction reached a minimum. But at a field intensity of 40 and 50 Hz, the time velocity of bacteria reproduction decreased. Given that E.coli bacteria is a pathogen, and at the same time a very important bacteria in scientific activities, the results of this study could be used in procedures to increase and decrease the population of this bacteria population.