The cornea is composed of a multilayered epithelium, Bowman's membrane, stroma, Descemet's membrane, and endothelium. The corneal endothelium (CE) is a single layer of hexagonal cells that separates the corneal stroma from the aqueous humor of the anterior chamber. Transparency of the cornea is maintained by regulation of stromal hydration through the barrier and pump functions of the CE, and c...

The threat of invasive species has increased with the expansion of global transportation. In the United States, zebra mussels became a problem by the early 1990’s when they were introduced by ballast water into Lake St. Clair in 1988. In 2007, a new deterministic discrete-time model for zebra mussel populations was proposed by Casagrandi. We show how this model produces periodic, stable, and ch...

One of the most striking development in the world trading system since the mid 1990s is a surge in Regional Trade Agreements (RTAs). From about 50 till 1990, the number of RTAs notified to the World Trade Organization (WTO) has crossed 250 in 2003 and estimates indicate that over 300 RTAs will be in effect by 2007. Initially WTO encouraged the growth of RTAs because it believed that regional in...