A purely communicative variant of P systems was considered recently, based on the trans-membrane transport of couples of chemicals. When using both symport rules (the chemicals pass together in the same direction) and antiport rules (one chemical enters and the other exits a membrane), one obtains the computational completeness, and the question was formulated what happens when only symport rul...

Recently, our attention has focused on the low level detection of many antibiotics, pharmaceuticals, and other organic chemicals in water resources. The limited studies available suggest that urban or rural streams receiving wastewater effluent are more susceptible to contamination. The purpose of this study was to evaluate the occurrence of antibiotics, pharmaceuticals, and other organic chemi...