Several decades ago it was reported that when adult male rats were exposed to a single injection of 50 mg/kg body weight ethane dimethanesulfonate (EDS) and mated with untreated females, average litter size was significantly reduced as early as 2 weeks later. Recently, we demonstrated that EDS exerts multiple effects in the epididymis of adult rats. Some of these effects were independent of red...

Different strategies for Nile tilapia (Oreochromis niloticus) culture in ponds with a series of progressive inputs were compared. The sequential experimental stages to increase fish production through intensification were: 1) triple superphosphate (TSP) only; 2) chicken manure only; 3) chicken manure supplemented with urea or urea and TSP; 4) urea and TSP; 5) continually supplemental feeding; 6...

A healthy meal is a complex cocktail of macroand micro-nutrients. Yet, when it comes to discussing diets, we typically consider calories to be the central drivers of hunger and obesity, disregarding other factors. The threat that climate change poses to agricultural productivity and food security around the world, especially in the tropics and sub-tropics, is also usually analysed only in terms...

This paper uses cross-country panel data to estimate the agronomic inputs that lead to cereal yield improvements and the consequences for countries' processes of structural change. The results suggest a clear role for fertilizer, modern seeds and water in boosting yields. It then estimates empirical links in developing economies between increased agricultural yields and economic growth; in part...

-Nitroheterocycles have been shown to inhibit the incorporation of 3H-TdR by cultured L-929 cells, and the degree ofinhibition is related to their electronaffinity. On the basis of their chemical reactivity and potential clinical utility, nitrofurazone, misonidazole and metronidazole were selected for more detailed studies of the mechanism of inhibition of DNA synthesis. Double-isotope labellin...

Mammalian sperm acquire fertilizing capacity after residing in the female tract, where physiological changes named capacitation take place. In animals with external fertilization as amphibians, gamete interactions are first established between sperm and molecules of the egg jelly coat released into the medium. Since dejellied oocytes are not normally fertilized, the aim of this study was to det...

Self-fertilizing species often harbor less genetic variation than cross-fertilizing species, and at least four different models have been proposed to explain this trend. To investigate further the relationship between mating system and genetic variation, levels of DNA sequence polymorphism were compared among three closely related species in the genus Caenorhabditis: two self-fertilizing specie...