The CNLS systems may also model beam propagation inside crystals, water wave interactions, biophysics , finance , and oceanography , and in the field of communications such equations have been employed to describe pulse propagation along orthogonal polarization axes in nonlinear optical fibers and in wavelength-division-multiplexing systems .
As mentioned above, such type of CNLS system can be used to model a variety of physical phenomena.
In the case of CNLS models for pulse propagation in optical fibers, this class of cross-mode terms account for the coherent nonlinear interaction between two linear polarizations of the electromagnetic waves.
Thus, we consider the complete integrable CNLS equations as
Although the investigations into the CNLS equations have been conducted via the different methods including Darboux transform , the Hirota method [31, 32], extended Jacobi's elliptic function method , Painleve's analysis , and Backlund transformation [33-36] and many soliton solutions have been derived including one-soliton solutions, there are still several points to continue to explore as follows:
1) Analysis of the CNLS equations and extraction of the bilinear system based on the Hirota method.
In 2002, the CNLS started a programme to prevent vertical HIV transmission, which includes voluntary HIV counselling and testing for all women receiving antenatal care.
14) In 2007, 65% of Burkinabes who needed antiretrovirals did not receive them, (7) even though that same year the CNLS succeeded in lowering the cost of treatment by 70%.
Although the CNLS
was later opened up to include religious groups, NGOs and other partners, it never managed to lead a multisectoral approach to HTV/AIDS.