Organisms with external fertilization are often sperm limited, and in echinoids, larger eggs have a higher probability of fertilization than smaller eggs. This difference is thought to be a result of the more frequent sperm-egg collisions experienced by larger targets. Here we report how two components of egg target size, the egg cell and jelly coat, contributed to fertilization success in a se...

To explore the possibility of providing additional reinforcement to bio-cemented sand through fiber inclusions, a series sand-fiber mixtures were prepared by mixing with three types fibers (polypropylene fiber, basalt and carbon fiber) at different contents (0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 0.8% volume sand). Each mixture was subjected two cycles controlled microbial-induced calcite precipitatio...

Complex life cycles have evolved independently numerous times in marine animals as well as in disparate algae. Such life histories typically involve a dispersive immature stage followed by settlement and metamorphosis to an adult stage on the sea floor. One commonality among animals exhibiting transitions of this type is that their larvae pass through a 'precompetent' period in which they do no...

to understand the relationship between natural physicochemical properties of soil and abundance of citrus root nematode (tylenchulus semipenetrans), a survey was conducted during 2009-2010 in some 37 citrus orchards, in kohgilouyeh va boyerahmad province, iran. distribution of the citrus nematode was determined by collecting random samples from the soil and citrus plant roots, extracting and en...

One of the ordinary methods to protect, rehabilitate, and enhance an ecosystemfunction in arid and semi-arid areas of the world is sand dune stabilization using biologicalpractices. Plantation of species on the soil plays a great role in sustainable management ofthe ecosystem. This research studies the effects of cultivation of Haloxylon ammodendronand Atriplex canescens on physical-chemical ch...