For this problem, we were tasked with identifying the growth pattern of rats on a deserted island. There are no predators of the rats on the island, so the rats would be able to reproduce at an uncontrollable pace. The problem provides a starting point of two rats, one male, and the other female.
This article has been cited by other articles in PMC. POW is the only tick-borne flavivirus endemic to the western hemisphere, where it is transmitted mainly between Ixodes cookei and groundhogs Marmota monax. Deer tick virus DTVa genotype of POW that has been frequently isolated from deer ticks Ixodes scapularisappears to be maintained in an enzootic cycle between these ticks and white-footed mice Peromyscus leucopus.
DTV has been isolated from ticks in several regions of North America, including the upper Midwest and the eastern seaboard. The incidence of human disease due to POW is apparently increasing. Previous analysis of tick-borne flaviviruses endemic to North America have been limited to relatively short genome fragments.
We therefore assessed the evolutionary dynamics of POW using newly generated complete and partial genome sequences. Maximum-likelihood and Bayesian phylogenetic inferences showed two well-supported, reciprocally monophyletic lineages corresponding to POW and DTV.
Bayesian skyline plots based on year-of-sampling data indicated no significant population size change for either virus lineage. Statistical model-based selection analyses showed evidence of purifying selection in both lineages. Our findings confirm that POW and DTV sequences are relatively stable over time, which suggests strong evolutionary constraint, and support field observations that suggest that tick-borne flavivirus populations are extremely stable in enzootic foci.
Although data from field-based studies of POW and DTV are scant, two recent reports demonstrated that infection rates in ticks in a DTV focus in northern Wisconsin were remarkably stable over a year period Brackney et al. Therefore, POW and DTV appear to be similar to many other tick-borne agents in that they are nidal infections that are maintained in highly stable enzootic foci for long periods of time.
Human cases have increased markedly between the periods — and — Hinten et al. These observations raise the possibility that these agents may be an emerging burden to public health in regions of North America where they are enzootic. Accordingly, we sought to determine whether the apparent emergence of tick-borne flavivirus disease in North America may be driven by increases in the virus population size, reasoning that the well-documented expansion in the population of deer ticks that has occurred in recent decades may have consequently increased the population size, or sizes, of their pathogens.
We then estimated the divergence time between lineages and tested for evidence of positive selection. Finally, population dynamics were inferred under a Bayesian framework, thus shedding light on the mechanisms influencing the epidemiology of POW in North America.Urbanization and Growth Michael Spence Patricia Clarke Annez Robert M.
Buckley Editors. Urbanization and Growth Commission on Growth and Development. Rural Population in China and India, – 5 Per Capita Income in China and India, – 5 Urbanization and Per Capita GDP in Brazil, – 6.
Jan 24, · Greater Tokyo – 34,,, pc growth Photo: ALAMY PM GMT 24 Jan A mega-city is usually defined as a metropolitan area with a total population of more than 10 million people. A certain population A, is experiencing exponential growth. Population size = 50 Births = 10 Death = 4 Population size = 50 Births = 10 Death = 4 A.
Calculate the individual growth rate (r). Overall, the vast majority of U.S. population growth is concentrated in the South and West. Likewise, the cities topping this list are mostly scattered through states like Texas, California, North. Cell population growth in the rat parotid gland during postnatal development Cell population growth in the rat parotid gland during postnatal development Taga, R; Sesso, A The growth kinetics of different cell populations in the rat parotid was studied.
The evolution of the frequency and absolute number of each cell type was determined morphometrically by a particle. The Compound Annual Growth Rate (CAGR) is the mean annual growth rate of an investment over a specified period of time longer than one year. The Compound Annual Growth Rate (CAGR) is .