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Ecological and evolutionary dynamics can occur on similar timescales. However, theoretical predictions of how rapid evolution can affect ecological dynamics are inconclusive and often depend on untested model assumptions. Here we report that rapid prey evolution in response to oscillating predator density affects predator-prey (rotifer-algal) cycles in(More)
Food restriction of adult rodents increases lifespan, with commensurate attenuation of age-related pathological lesions in many organs, as well as attenuation of normal ageing changes that are distinct from gross lesions. Previous work showed that chronic food restriction attenuated age-associated astrocyte and microglial hyperactivity in the hippocampal(More)
Trophic relationships, such as those between predator and prey or between pathogen and host, are key interactions linking species in ecological food webs. The structure of these links and their strengths have major consequences for the dynamics and stability of food webs. The existence and strength of particular trophic links has often been assessed using(More)
In a recent study (Fussmann et al. 2005), we used an experimental rotifer–algal system to show that the functional response of the consumer depends on the resource but not on the consumer concentration. We concluded that resource dependence should be the norm in dynamical mathematical models. Jensen et al. (2007) published a Comment on our paper in which(More)
We estimated the contributions of sedimentation and cell lysis to the loss of two large phytoplankton species (Fragilaria crotonensis and Staurastrum dorsidentiferum) in Lake Biwa. Major loss process differed between species, and large phytoplankton did not necessarily function as a nutrient sink. The spring bloom of F. crotonensis was terminated by(More)
Character evolution that affects ecological community interactions often occurs contemporaneously with temporal changes in population size, potentially altering the very nature of those dynamics. Such eco-evolutionary processes may be most readily explored in systems with short generations and simple genetics. Asexual and cyclically parthenogenetic(More)
Ecologists have increasingly focused on how rapid adaptive trait changes can affect population dynamics. Rapid adaptation can result from either rapid evolution or phenotypic plasticity, but their effects on population dynamics are seldom compared directly. Here we examine theoretically the effects of rapid evolution and phenotypic plasticity of(More)
We used microcosm systems to test whether simple mathematical models can be valid descriptions of population and community dynamics. Our conclusion is that a priori mathematical formulations of interacting populations are unlikely to produce completely satisfying predictions because they tend to ignore important biological mechanisms. We employed the(More)
During aging, rodent and human brains show progressive increases in the levels of glial fibrillary acidic protein (GFAP) mRNA and protein. The role of transcription was investigated by in situ hybridization, using an intron-containing cRNA probe as a measure of primary GFAP transcripts. We found parallel age-related increases in GFAP intron RNA in the(More)
The disappearance of norepinephrine (NE) from brown adipose tissue, heart, and pancreas in vivo has been examined in rats with ventromedial hypothalamic (VMH) lesions and in appropriate control rats. Two weeks after the introduction of these lesions, the rate of NE turnover following blockade of NE synthesis with alpha-methyl-p-tyrosine was significantly(More)