Biological invasions are increasingly frequent and have dramatic ecological and economic consequences. A key to coping with invasive species is our ability to predict their rates of spread. Traditional models of biological invasions assume that the environment is temporally constant. We examine the consequences for invasion speed of periodic and stochastic £uctuations in population growth rates...

Biological invasions are increasingly frequent and have dramatic ecological and economic consequences. A key to coping with invasive species is our ability to predict their rates of spread. Traditional models of biological invasions assume that the environment is temporally constant. We examine the consequences for invasion speed of periodic and stochastic fluctuations in population growth rate...

The drift paradox asks how stream-dwelling organisms can persist, without being washed out, when they are continuously subject to the unidirectional stream flow. To date, mathematical analyses of the stream paradox have investigated the interplay of growth, drift and flow needed for species persistence under the assumption that the stream environment is temporally constant. However, in reality,...

important cut flowers in tropical and sub tropical areas of the world and has the seventh rate of production between all cut flowers of Iran. In order to investigate different effects of storage temperatures (8 weeks at 4 °C, 4 weeks at 4 °C + 4 weeks at 20 °C, 8 weeks at 12 °C, 4 weeks at 12 °C+ 4 weeks at 20 °C and 8 week at 20 °C) and different concentrations of gibberellic acid (0, 150 and ...

The speed at which biological range expansions occur has important consequences for the conservation management of species experiencing climate change and for invasion by exotic organisms. Rates of dispersal and population growth are known to affect the speed of invasion, but little is known about the effect of having a community of dispersal phenotypes on the rate of range expansion. We use re...

telemedicine has changed the way of health care. it is an indispensable tool in the hands of doctors to accelerate and facilitate the process of data interchange. wireless networks consist of small nodes with communications capabilities. development of wireless networks of telemedicine system is highly demanded since these networks promise a wide range of potential applications. in this paper t...