The framework ecological stoichiometry uses elemental composition of species to make predictions about growth and competitive ability in defined elemental supply conditions. Although intraspecific differences in stoichiometry have been observed, we have yet to understand the mechanisms generating and maintaining such variation. We used variation in phosphorus (P) content within a Daphnia specie...

francoeuria undulata (l.) lack is often synonymous with two species of the genus pulicaria,i.e. pulicaria undulata (l.) c.a. mey and pulicaria crispa (forssk.) olive, which are oftenincluded under the genus francoeuria. the essential oil yield and compositions in the fivenatural populations of francoeuria undulata from fars province in southern iran weredetermined by gc and gc/ms analysis. the ...

Pulicaria gnaphalodes has various biological activities and is used as an herbal plant in traditional medicine. The major components of the aqueous extract of this plant are flavonoids, terpenoids and phenolic compounds which could be a good candidate for dyeing of wool fibers. In this study, the aerial part of Pulicaria gnaphalodes plant was extracted and used for the colorat...

Microsatellite markers were developed for population genetic analyses of the Neotropical tree Eugenia dysenterica DC (Myrtaceae), after construction of a shotgun genomic library for microsatellite discovery. Nine primers were designed, of which 5 yielded amplified product. These primers were polymorphic for 97 individuals collected in 3 distinct localities. The number of alleles per locus (prim...

1. We used a zooplankton metacommunity to ask how dispersal, genetic drift and selection act to determine the local and regional distributions of trait variation. Since the formation of the lakes 80 years ago, cladoceran species have sorted into local assemblages that cluster by lake depth. Given this species sorting, we ask whether intraspecific variation in an ecologically important phenotypi...

Background and objectives: Several natural compounds have been identified for the treatment ofleishmaniasis. Due to a few safe drugs and the side effects caused by available chemotherapy, some new drugs for treatment of leishmaniasis are requested.  The genus Pulicaria (Asteraceae) is represented in the flora of Iran by five species. Phytochemical studies on Pulicaria...

* corresponding author, e-mail : [email protected] Abstract: A sesquiterpene lactone 1 Lacinin and a sesquiterpene lactone glucoside 2 Laciniside, were isolated from the flowers of Pulicaria laciniata. Their structures were elucidated by extensive spectroscopic methods including 1D-( 1 H and 13 C) and 2D-NMR experiments, (CHcorr, HMBC, 1 H1 H COSY and NOESY) as well as high resolution E...

Competition structures ecological communities and alters host-pathogen interactions. In environmentally transmitted pathogens, an infection-resistant competitor may influence infection dynamics in a susceptible species through the negative impacts of competition (e.g., by reducing host density or causing nutritional stress that increases susceptibility to infection) and/or the positive impacts ...

Theoretical models suggest that overlapping generations, in combination with a temporally fluctuating environment, may allow the persistence of competitors that otherwise would not coexist. Despite extensive theoretical development, this "storage effect" hypothesis has received little empirical attention. Herein I present the first explicit mathematical analysis of the contribution of the stora...