Previous experiments with mouse chimeras demonstrated that cellular competition for antigen-specific survival signals plays a crucial role in the maintenance of the naive B cell repertoire. Transgenic (Tg) B cell populations in these chimeras have a shortened lifespan and poor competitive abilities as compared to more diverse non-Tg populations in the same mice. We develop a mathematical model ...

A division of labour occurs in colonies of the trematode Philophthalmus sp. within their first intermediate hosts. Two castes exist: one which reproduces and one which does not reproduce. It has been hypothesized that the benefit of the non-reproductive caste is in competitive interactions. Evidence for this from past experiments with Philophthalmus sp. colonies has been contradictory: the non-...

The nature and intensity of intraspecific competition can vary greatly among taxa, yet similarities in these interactions can lead to similar population dynamics among related organisms. Variation along the spectrum of intraspecific competition, with contest and scramble competition as endpoints, leads to vastly different responses to population density. Here we investigated the diversity of in...

optimum management of intra- and interspecific competitions are key subject in most agroecosystems. the objective of this experiment was the study effect of intra- and interspecific competitions and n rates on yield and yield components of wheat which was carried out in agricultural faculty of shahid chamran university of ahvaz during 2011-2012. the experimental design was split–plot based on r...

Growth chamber experiments with rapid-cycling Brassica rapa were designed to estimate the signsand magnitudes ofthe genetic correlationsfor plant performance in each ofthree conditions: no-competition (isolated plants), intraspecific competition, and interspecific competition with Raphanus sativa. Biomass and flower number were highest in the no-competition treatment, intermediate under intrasp...

The predator-prey model with stage structure for predator is generalized in the context of ecoepidemiology, where the prey population is infected by a microparasite and the predator completely avoids consuming the infected prey. The intraspecific competition of infected prey is considered. All the equilibria are characterized and the existence of a Hopf bifurcation at the coexistence equilibriu...

aim: this study investigates the intraspecific competition, for food and density amongst larvae of anopheles stephensi (main malaria vector in south iran). material & methods: the effects of 4 selected food quantities (1x,2x,4x,6x) and 5 larval densities (0.1 to 3 larva/cm2) were tested individually or in combination on 7 biological indexes of the vector and the results were statistically ...