Nothing Lasts Forever: Environmental Discourses on the Collapse of Past Societies

The study of the collapse of past societies raises many questions for the theory and practice of archaeology. Interest in collapse extends as well into the natural sciences and environmental and sustainability policy. Despite a range of approaches to collapse, the predominant paradigm is environmental collapse, which I argue obscures recognition of the dynamic role of social processes that lie at the heart of human communities. These environmental discourses, together with confusion over terminology and the concepts of collapse, have created widespread aporia about collapse and resulted in the creation of mixed messages about complex historical and social processes

Development of Novel Biodegradable Polymeric Nanoparticles-in-Microsphere Formulation for Local Plasmid DNA Delivery in the Gastrointestinal Tract

There is a critical need for development of novel delivery systems to facilitate the translation of nucleic acid-based macromolecules into clinically-viable therapies. The aim of this investigation was to develop and evaluate a novel nanoparticles-in-microsphere oral system (NiMOS) for gene delivery and transfection in specific regions of the gastrointestinal (GI) tract. Plasmid DNA, encoding for the enhanced green fluorescent protein (EGFP-N1), was encapsulated in type B gelatin nanoparticles. NiMOS were prepared by further protecting the DNA-loaded nanoparticles in a poly(epsilon-caprolactone) (PCL) matrix to form microspheres of less than 5.0 μm in diameter. In order to evaluate the biodistribution following oral administration, radiolabeled (111In-labeled) gelatin nanoparticles and NiMOS were administered orally to fasted Balb/C mice. The results of biodistribution studies showed that, while gelatin nanoparticles traversed through the GI tract fairly quickly with more than 54% of the administered dose per gram localizing in the large intestine at the end of 2 h, NiMOS resided in the stomach and small intestine for relatively longer duration. Following oral administration of EGFP-N1 plasmid DNA at 100 μg dose in the control and test formulations, the quantitative and qualitative results presented in this study provide the necessary evidence for transfection potential of NiMOS upon oral administration. After 5 days post-administration, transgene expression in the small and large intestine of mice was observed. Based on these results, NiMOS show significant potential as novel gene delivery vehicle for therapeutic and vaccination purposes