Plants must respond appropriately to a broad array of abiotic and biotic factors in the attempt to accumulate nutrient reserves and reach reproductive maturity. To complicate matters, their stockpile of nutrients makes them prime targets for pathogen attack. Phytopathogenic bacteria, fungi, and viruses all make raids on the stockpile, yet most plants are able to remain disease free. Plants have...

While dietary restriction usually increases lifespan, an intermittent feeding regime, where periods of deprivation alternate with times when food is available, has been found to reduce lifespan in some studies but prolong it in others. We suggest that these disparities arise because in some situations lifespan is reduced by the costs of catch-up growth (following the deprivation) and reproducti...

Using the idea that life-history parameters are subject to natural selection and should approach values that are stable optima, with the population immune to invasion by mutant individuals, we derive an analytic expression for the evolutionarily stable dispersal rate in a stochastic island model with random site extinction. The results provide interesting contrasts between three different optim...

To the editor: In their recent article on the large outbreak of measles in Merseyside, England, Vivancos et al. [1] obtained a basic reproductive number R0 of 1.2 in week 3 after the start of the outbreak. This result could suggest that measles viruses are less infectious in recent outbreaks than in the pre-vaccination era, when the basic reproductive number R0 ranged from 11 to 18 [2]. The bas...

In this paper we study the two-phase size-structured population model with infinite states-at-birth and distributed delay in birth process. The model distinguishes individuals by two different status: the 'reproductive' stage and the 'nonreproductive' stage. We establish the well-posedness for this model and show that the solution of this model exhibits asynchronous exponential growth by means ...

Short durations in a range of standard durations are typically overreproduced and long durations underreproduced ('Vierordt's Law'). This contextual distortion may result from each trial assimilating the central tendency of the preceding series. We examine whether responses as well as standard durations contribute to this distortion. Two experiments using nonequal-setting ratio tasks are descri...

Idifferently may result in better prediction of teenage behavior. To compare the perceptions of adolescents and adults on 20 personality characteristics, rating tables originally constructed by Hess and Goldblatt (1957) were given to 35,Hispanic and Anglo high school students, who took complementary forms home for their'parents to complete. Redults were analyzed for possible differences by age,...

To gain a deeper understanding of how environmental conditions affect brain plasticity, brain size was explored across different seasons using the invasive round goby Neogobius melanostomus. The results show that N. melanostomus had heavier telencephalon in the spring compared to the autumn across the two years of study. Furthermore, fish in reproductive condition had heavier telencephala, indi...

objectives: the purpose of this study was to compare the accuracy of implant position transfer and surface detail reproduction using two impression techniques and materials. materials and methods: a metal model with two implants and three grooves of 0.25, 0.50 and 0.75 mm in depth on the flat superior surface of a die was fabricated. ten regular-body polyether (pe) and 10 regular-body polyvinyl...