to study the physiological and morphological relationships of two clover species affected by herbicides, pursuit experiment in a factorial based on randomized completely design with 3 replications at the damavand in 2012. the first factor consisted of two species of trifolium pretense l. and trifolium alexandrinum l. and the second factor consisted of three levels of herbicide pursuit (0, 0.5, ...

the experiment was conducted in order to evaluate of competitive and economic indices in canola and pea intercropping at different rates of nitrogen fertilizer at shahrekord university research farm during 1390 - 1391. intercropping and sole cropping treatments (100% canola; 66% canola + 33% pea, 50% canola + 50% pea; 33% canola + 66% pea; 100% pea) were evaluated as the first factor and nitrog...

This study estimated the length-weight relationship, sex ratio and population parameters of mantis shrimp, Harpiosquilla harpax from the coastal waters of Pantai Remis, Perak, Malaysia between February 2012 and October 2012. Total length and weight of 804 specimens of H. harpax were measured and the sex ratio was 1: 0.83 (M: F). Males of H. harpax were dominant over the females throughout the s...

Sex allocation theory offers excellent opportunities for studying the precision of adaptation. One of the best-supported areas in the field of sex allocation is Hamilton's theory of local mate competition, which predicts female-biased offspring sex ratios when populations are structured such that mating takes place locally before females disperse. As predicted by local mate competition theory, ...

Anaemia in falciparum malaria is associated with an increased risk of gametocyte carriage, but its effects on transmission have not been extensively evaluated in malarious children. Plasmodium falciparum gametocyte carriage, emergence, clearance, population sex ratios (SR) (defined as the proportion of gametocytes that are male), inbreeding rates and temporal changes in SR were evaluated in 840...

PURPOSE We measured offspring sex ratios in a resident insectivorous passerine bird, the Great tit Parus major, to find out whether metal pollution around a Finnish copper smelter would bias sex ratios in this territorial forest bird species. Besides a direct effect of pollutants, we were interested in possible indirect effects of pollution-related resource limitation, i.e., changes in food qua...

Adaptive theory predicts that mothers would be advantaged by adjusting the sex ratio of their offspring in relation to their offspring's future reproductive success. Studies investigating sex ratio variation in mammals, including humans, have obtained notoriously inconsistent results, except when maternal condition is measured around conception. Several mechanisms for sex ratio adjustment have ...

In fig wasps, mating takes place among the offspring of one or a few foundress mothers inside the fig from which mated females disperse to found new broods. Under these conditions, related males will compete with each other for mating and several studies have shown female bias in brood sex ratios as a response to Local Mate Competition (LMC). Studying Pegoscapus tonduzi which pollinates Ficus c...

In a verbal model, Trivers and Willard proposed that, whenever there is sexual selection among males, natural selection should favor mothers that produce sons when in good condition but daughters when in poor condition. The predictions of this model have been the subject of recent debate. We present an explicit population genetic model for the evolution of a maternal-effect gene that biases off...